The cake underneath is a plain cocoa batter thinned with hot coffee, which keeps it dark and moist. It goes into a 9-by-13-inch dish on its own.
The swirl is cream cheese, peanut butter, butter and powdered sugar beaten smooth and dropped over in large spoonfuls. It is barely swirled, so the cake bakes with distinct marbled pockets rather than an even layer.
How Much to Swirl
The marbling is decided in about ten seconds.
Look at the surface after one pass with the knife. What do you see?
Clear light pockets against dark batter
Stop swirling and put the dish in the oven.
The colours are blending into one shade
Stop immediately and bake as is.
Over-swirling turns the marbled pockets into a uniform layer.
How to Make It
Dish greased
Heat the oven to 350°F. Grease a 9-by-13-inch baking dish.
Chocolate batter
Whisk the flour, sugar, cocoa, baking powder, baking soda and salt. Add the eggs, milk, oil and vanilla and mix until smooth, then whisk in the hot coffee or water.
Batter poured
Pour the chocolate batter into the dish.
Swirl dropped on
Beat the cream cheese, 1/2 cup peanut butter, softened butter and powdered sugar until smooth. Drop large spoonfuls over the chocolate batter and swirl only lightly so distinct marbled pockets remain.
Baked
Bake 38 to 42 minutes, until the chocolate cake is set around the swirls and a tester in a cake-only area has moist crumbs but no raw batter.
Drizzled
Cool at least 30 minutes and drizzle with the warmed peanut butter before serving.
Ingredient Notes
- Cream cheese
- Eight ounces, beaten with peanut butter and butter for the swirl.
- Hot coffee or hot water
- Three-quarters of a cup, whisked in last to thin the batter.
- Peanut butter for drizzling
- A third of a cup, warmed until pourable.
Success Tips
- Drop the swirl in a few big spoonfuls rather than many small ones.
- Drag a knife through twice at most; more and the marbling disappears.
- Check the cake in a spot away from the swirl so the reading is accurate.
Why This Recipe Works
- Hot coffee deepens the cocoa without leaving a coffee flavour.
- Large spoonfuls keep the swirl in pockets instead of streaks.
- Cream cheese sets the peanut butter mixture so it stays put as it bakes.
- Testing in a cake-only area avoids mistaking the soft swirl for raw batter.
Serving Ideas
Cut squares straight from the dish and spoon extra warm peanut butter over each.
Storage and Reheating
Refrigerate
Cover and refrigerate once cooled; the cream cheese swirl needs the cold.
Frequently Asked Questions
How much should I swirl?
Only lightly. Distinct pockets of the peanut butter mixture should remain.
How do I test it?
Put the tester into a cake-only area; the swirl stays soft even when the cake is done.
