There is something special about cutting into a Bundt cake and finding a surprise in the middle. Tunnel of Fudge Cake has that classic Bundt silhouette on the outside, but once you slice into it, a rich chocolate cheesecake layer is waiting inside. Chocolate and cheesecake, baked right into one gorgeous package.
The cake itself is rich and deeply chocolatey, with a splash of coffee to intensify the flavor. At the center, a creamy chocolate cheesecake filling stays soft and fudgy even after baking, creating that signature “tunnel” when sliced. Once cooled, a simple chocolate ganache poured over the top adds one more layer of chocolate without complicating the process. The recipe serves 8 to 10, and this guide covers the complete method, why each ingredient matters, the details that make the tunnel effect work, and plenty of ideas for variations, storage, and serving.
What Is Tunnel of Fudge Cake?
Tunnel of Fudge Cake is a doctored chocolate cake mix baked in a Bundt pan with a chocolate cheesecake filling spooned into the batter before baking. As the cake bakes, the surrounding batter rises and sets while the dense, creamy filling in the center stays soft, forming a ribbon of fudgy cheesecake running through the finished cake. The name describes exactly that: a tunnel of rich, fudge-like filling hidden inside.
Keeping the filling away from the sides and the center hole of the Bundt pan is the key technique. Placed as a ring in the middle of the batter, it bakes surrounded by cake rather than touching the pan directly, which is what allows it to stay soft and distinct instead of blending into the surrounding batter.
Why You’ll Love This Recipe
- A built-in surprise. A fudgy chocolate cheesecake center hidden inside a classic Bundt cake.
- Starts with a cake mix. Elevated with coffee and a homemade filling, but still simple to make.
- Rich, deep chocolate flavor. Coffee intensifies the chocolate without adding a coffee taste.
- A simple finishing touch. A quick ganache poured over the top looks impressive with minimal effort.
- Feeds a crowd. One Bundt cake serves 8 to 10.
- Great for special occasions. Birthdays, holidays, or dinners with friends and family.
- Make-ahead friendly. The cake can be baked a day ahead and glazed before serving.
Ingredients You’ll Need
The recipe comes together in three parts: the cheesecake filling, the cake, and the ganache.
For the Cheesecake Filling
1 cup semisweet chocolate chips. Melted and folded into the cream cheese mixture, this is what gives the filling its rich, fudgy chocolate flavor.
1 package (8 ounces) cream cheese, room temperature. Cream cheese forms the base of the filling, giving it a smooth, tangy richness. It needs to be fully softened to blend without lumps.
2 tablespoons granulated sugar. A modest amount of sugar sweetens the filling without making it overly sweet, since it needs to balance against the rich cake and ganache.
2 tablespoons corn syrup. Corn syrup adds moisture and helps keep the filling soft and fudgy rather than firm, even after baking.
1 egg. The egg gives the filling just enough structure to hold its shape as a distinct layer, without turning it into a firm cheesecake.
1 tablespoon heavy cream. Cream loosens the filling slightly, helping it blend smoothly and spoon easily into the batter.
For the Cake
1 box (15.25 ounces) chocolate cake mix. This is the simple, reliable base of the cake.
1 cup coffee, room temperature. Coffee deepens and intensifies the chocolate flavor without making the cake taste like coffee.
½ cup canola oil. Oil keeps the cake moist, standard for preparing a boxed cake mix.
3 eggs. Eggs provide structure and richness to the batter.
For the Ganache
⅔ cup heavy cream. Heated until it just starts to bubble, this is what melts the chocolate into a smooth, pourable ganache.
⅔ cup semisweet chocolate chips. Melted into the warm cream, these form the glossy, rich topping that finishes the cake.
Equipment
- A 10-inch Bundt pan
- A medium bowl, for the filling
- A large bowl, for the cake batter
- A microwave-safe bowl, for melting chocolate
- A hand mixer or whisk
- A wire rack
- A serving plate
How to Make Tunnel of Fudge Cake, Step by Step
Step 1: Preheat the Oven and Prepare the Pan
Preheat your oven to 350°F (175°C). Grease and flour a 10-inch Bundt pan thoroughly, making sure to coat every ridge so the finished cake releases cleanly. Set it aside.
Step 2: Make the Cheesecake Filling Base
In a medium bowl, beat the cream cheese until smooth. Mix in the sugar, corn syrup, and egg until fully combined.
Step 3: Melt the Chocolate for the Filling
In a microwave-safe bowl, heat the 1 cup of chocolate chips in 30-second intervals, stirring between each one, until fully melted. Let the chocolate cool for 3 minutes, then mix it into the cream cheese mixture until smooth. Set the filling aside.
Step 4: Make the Cake Batter
In a large bowl, mix together the cake mix, coffee, oil, and eggs just until well combined. Pour the batter into the prepared Bundt pan.
Step 5: Add the Filling
Spoon the cream cheese mixture onto the batter in a ring shape in the center of the pan, keeping it away from the outer sides and the center hole. This placement is what creates the tunnel effect once the cake bakes and is sliced.
Step 6: Bake
Bake for 35 to 40 minutes, or until a toothpick inserted into the cake portion (not the filling) comes out clean.
Step 7: Cool and Invert
Allow the cake to cool in the pan for 10 to 15 minutes, then invert it onto a serving plate to finish cooling completely.
Step 8: Make the Ganache
Once the cake has cooled, heat the heavy cream in a microwave-safe bowl until it just starts to bubble. Add the chocolate chips to the bowl and let it stand for 1 to 2 minutes to soften. Stir until smooth and glossy.
Step 9: Glaze and Set
Drizzle the ganache over the inverted, cooled cake. Allow the ganache to set for at least 30 minutes before slicing and serving.
Recipe Card
Tunnel of Fudge Cake
- Yield: 8 to 10 servings
- Prep time: 25 minutes
- Cook time: 35 to 40 minutes
- Inactive time: 45 minutes
- Course: Dessert
Cheesecake Filling Ingredients
- 1 cup semisweet chocolate chips
- 1 package (8 oz) cream cheese, room temperature
- 2 tablespoons granulated sugar
- 2 tablespoons corn syrup
- 1 egg
- 1 tablespoon heavy cream
Cake Ingredients
- 1 box (15.25 oz) chocolate cake mix
- 1 cup coffee, room temperature
- ½ cup canola oil
- 3 eggs
Ganache Ingredients
- ⅔ cup heavy cream
- ⅔ cup semisweet chocolate chips
Instructions
- Preheat the oven to 350°F and grease and flour a 10-inch Bundt pan.
- Beat the cream cheese until smooth, then mix in the sugar, corn syrup, and egg.
- Melt the 1 cup of chocolate chips in 30-second microwave intervals, stirring between each. Cool 3 minutes, then mix into the cream cheese mixture.
- Mix the cake mix, coffee, oil, and eggs until just combined. Pour into the prepared pan.
- Spoon the cream cheese mixture onto the batter in a ring in the center, away from the sides and middle hole.
- Bake 35 to 40 minutes, until a toothpick in the cake portion comes out clean.
- Cool 10 to 15 minutes, then invert onto a serving plate to finish cooling.
- Heat the cream until it starts to bubble, add the chocolate chips, let stand 1 to 2 minutes, then stir until smooth.
- Drizzle the ganache over the cake and let set at least 30 minutes before serving.
Tips for the Best Tunnel of Fudge Cake
Grease the Pan Thoroughly
Bundt pans are notorious for sticking, especially with a cake that has a dense filling. Coat every ridge well with butter or baking spray.
Keep the Filling Away from the Edges
Spooning the cheesecake mixture in a ring in the center, away from the pan’s sides and the middle tube, is essential for the tunnel effect to form correctly as the cake bakes.
Soften the Cream Cheese Fully
Room-temperature cream cheese blends smoothly. Cold cream cheese leaves lumps that are hard to work out.
Cool the Melted Chocolate Before Mixing
Letting the chocolate cool for the full 3 minutes prevents it from cooking the egg in the cream cheese mixture when combined.
Test the Toothpick in the Cake, Not the Filling
Since the filling stays intentionally soft, always check for doneness in a section of visible cake batter rather than where the filling sits.
Let the Cake Cool Before Glazing
Pouring ganache over a warm cake will cause it to melt and run off completely rather than setting into a glossy coating.
Heat the Cream Just Until Bubbling
Overheating the cream for the ganache can affect its texture. Warm it just until it starts to bubble at the edges.
Troubleshooting Common Problems
My Cake Stuck to the Pan
The pan likely wasn’t greased thoroughly enough, especially in the ridges. Coat it generously next time and let the cake cool for the full 10 to 15 minutes before inverting.
My Tunnel Didn’t Form Properly
The filling may have been spooned too close to the edges or center hole of the pan, allowing it to touch the pan directly rather than staying fully surrounded by batter.
My Cake Seems Underbaked
Remember that the filling stays intentionally soft and fudgy. Always test doneness in a section of plain cake batter, not where the filling is.
My Ganache Is Too Thin
Let it sit for a few extra minutes to thicken slightly before pouring, or use a little less cream next time.
My Ganache Is Too Thick to Pour
Warm it very gently for a few seconds in the microwave, stirring in between, until it loosens to a pourable consistency.
My Ganache Slid Off the Cake
The cake was likely still warm. Let it cool completely before glazing.
Variations to Try
Espresso Boost
Use freshly brewed espresso in place of regular coffee for an even more intense chocolate flavor.
Mint Chocolate Version
Add a half teaspoon of mint extract to the ganache for a chocolate-mint twist.
Nutty Finish
Sprinkle chopped toasted pecans or walnuts over the ganache while it’s still wet for added crunch.
White Chocolate Drizzle
Add a thin drizzle of melted white chocolate over the ganache for a decorative, contrasting finish.
Salted Ganache
Sprinkle a pinch of flaky sea salt over the ganache before it sets for a sweet-and-salty finish.
Orange Chocolate
Add a teaspoon of finely grated orange zest to the cheesecake filling for a chocolate-orange flavor combination.
What to Serve With Tunnel of Fudge Cake
- A scoop of vanilla ice cream
- Fresh raspberries or strawberries, for a tart contrast
- Lightly sweetened whipped cream
- A cup of hot coffee or espresso
Make-Ahead, Storage, and Freezing
Make ahead: The cake can be baked a day in advance and glazed the next day, which also gives the flavors time to settle.
Room temperature: Store the glazed cake under a cake dome or loosely covered at room temperature for up to 2 days.
Refrigerator: Because of the cream cheese filling, refrigerate the cake if storing for longer than 2 days, for up to 5 days total. Let slices come to room temperature before serving for the best texture.
Freezing: Wrap the unglazed, fully cooled cake tightly in plastic wrap and foil, and freeze for up to 2 to 3 months. Thaw overnight in the refrigerator, then make the ganache fresh before serving.
Frequently Asked Questions
Can I taste the coffee in the finished cake?
Not directly. The coffee works behind the scenes to intensify and deepen the chocolate flavor rather than adding its own distinct taste.
Why does the filling stay soft after baking?
It’s designed that way. The small amount of egg gives it just enough structure to hold together as a distinct layer, while the corn syrup and cream keep it fudgy rather than firm.
Do I have to use a Bundt pan?
A Bundt pan is essential for this particular cake, since the tunnel effect depends on the ring shape and the filling being placed away from the center hole and sides.
Why do I need to test the toothpick in the cake portion only?
The filling stays intentionally soft and fudgy even when fully baked, so testing there would give a misleading result.
Can I make the ganache ahead of time?
Yes. Store it in the refrigerator, then gently rewarm it until pourable before using it.
How do I know when the cake is done?
A toothpick inserted into the cake portion, away from the filling, should come out clean, and the cake should feel set and spring back lightly when touched.
Does this cake need to be refrigerated?
Because of the cream cheese filling, it’s best refrigerated if you’re keeping it longer than 2 days.
Allergen Note
This cake contains corn (from the corn syrup), eggs, gluten, milk, and wheat. Always check the labels on your specific cake mix brand for additional allergen information if you are serving guests with dietary restrictions.
