Ingredients (with measurements)
Chocolate Sponge Cake
- ¾ cup all-purpose flour
- ¼ cup unsweetened cocoa powder
- 1 teaspoon baking powder
- ¼ teaspoon salt
- 4 large eggs, room temperature
- ¾ cup granulated sugar
- 2 tablespoons vegetable oil
- 1 teaspoon vanilla extract
- ¼ cup milk
Peanut Butter Filling
- ¾ cup creamy peanut butter
- ½ cup powdered sugar
- ½ cup heavy cream
- 1 teaspoon vanilla extract
Add-Ins
- 1 cup chopped peanut butter cups
Optional Chocolate Ganache Topping
- ½ cup heavy cream
- ¾ cup semi-sweet chocolate chips
These amounts are in line with other 10×15-inch chocolate roll cake recipes that use 4 eggs for structure, a modest amount of flour and cocoa for a flexible sponge, and cream-based peanut butter fillings with chopped peanut butter cups. The ganache ratio mirrors common Swiss roll toppings where equal-ish parts cream and chocolate are used for a pourable glaze that sets softly.
Equipment and prep
You’ll need a 10×15-inch jelly roll pan, parchment paper, an electric mixer, mixing bowls, a clean kitchen towel, and an offset spatula. These are the same tools recommended by most Swiss roll and cake roll recipes because they make rolling and filling easier and more precise.
Before you start the batter, preheat your oven to 350°F (175°C) and line the jelly roll pan with parchment, leaving an overhang on the long sides for easy lifting, then lightly grease the parchment. Lay a clean kitchen towel flat and dust it generously with powdered sugar; this classic step appears in nearly every cake roll recipe to help the hot cake release and prevent it from sticking when rolled.
Step-by-step: chocolate sponge
In a medium bowl, whisk together the flour, cocoa powder, baking powder, and salt so the leavening and cocoa are evenly distributed. Keeping the dry ingredients well mixed helps the sponge bake evenly, just as it does in other Swiss roll and chocolate sponge recipes.
In a separate large bowl, beat the eggs and granulated sugar on high speed for 4–5 minutes until the mixture is thick, pale, and at least doubled (often nearly tripled) in volume. This long whip time is a hallmark of sponge-style roll cakes and is crucial for the cake’s structure and flexibility, mimicking the technique used in other chocolate and peanut butter roll cakes where eggs provide much of the lift.
Add the vegetable oil, vanilla extract, and milk to the whipped eggs and sugar, mixing gently just until combined. The oil adds tenderness without weighing the sponge down, a trick several modern chocolate roll recipes use to keep the cake moist yet rollable. Gently fold the dry ingredients into the egg mixture with a spatula until just combined, taking care not to deflate the batter—this “light hand” with folding is emphasized in many sponge roll recipes to keep the cake airy.
Pour the batter into the prepared pan and smooth it into an even layer with an offset spatula, making sure it fills the corners. Bake for 10–12 minutes, or until the top springs back lightly when touched and the cake pulls just slightly from the edges, similar to the quick bake times you see in other 10×15-inch chocolate roll recipes.
Rolling the warm cake
As soon as the cake comes out of the oven, run a knife around the edges if needed, then invert it onto the prepared, sugar-dusted towel. Carefully peel off the parchment paper; most Swiss roll instructions stress doing this while the cake is still hot so the parchment releases cleanly without tearing.
Starting from a short side, roll the warm cake up together with the towel inside, forming a tight but gentle spiral. This rolling technique while the cake is hot is standard across roll cake recipes, because it sets a “memory” into the sponge that helps it roll again later without cracking. Let the rolled cake cool completely on a wire rack, seam side down, before unrolling to fill.
Peanut butter cup filling
In a mixing bowl, beat the creamy peanut butter and powdered sugar together until smooth and thick, similar to the start of a peanut butter mousse or frosting used in other roll cake fillings. Add the heavy cream and vanilla extract, then beat until the filling becomes lighter in color and fluffy, reaching a spreadable consistency that holds soft peaks.
This method mirrors the process for peanut butter mousse fillings where cream is beaten in to lighten the texture so it doesn’t squeeze out when the cake is rolled. Once the mixture is fluffy, fold in the chopped peanut butter cups so they’re evenly distributed throughout the filling, just as other peanut butter cup roll cakes stir in candy pieces for added flavor and texture.
If the filling seems too soft, chilling it briefly can help it firm up slightly, a tip that’s often shared in similar recipes for peanut butter mousse and candy-studded fillings.
Filling, rolling, and ganache
When the cake is completely cool, gently unroll it from the towel. It may curve slightly at the ends, but if it was rolled while hot, it should open without cracking much, resembling the behavior of other well-made chocolate Swiss rolls. Spread the peanut butter filling evenly over the surface, leaving a small border around the edges (about ½ inch) to prevent overflow as you re-roll.
Roll the cake back up starting from the same short side, this time without the towel, keeping it as tight as you can without squeezing filling out. Place the filled roll seam-side down on a serving platter or a wire rack set over a tray if you plan to cover it in ganache, a setup commonly recommended for ganache-topped Swiss rolls.
For the ganache, heat the heavy cream in a small saucepan or microwave-safe bowl until it’s steaming but not boiling. Pour the hot cream over the semi-sweet chocolate chips and let it sit for about 2 minutes, then stir until the mixture becomes smooth and glossy, matching the standard ganache method for roll cakes and tortes.
You can let the ganache cool slightly if it seems too thin, then drizzle or spread it over the cake roll. Many peanut butter chocolate roll recipes recommend chilling the cake for 30–60 minutes after applying ganache so it can set for cleaner slices, and your serving suggestions do the same.