Peanut Butter Cake

5 from 3 votes

If you love peanut butter, you will love this moist, old-fashioned peanut butter cake with a smooth and creamy peanut butter cream cheese frosting!

Prep Time30

Cook Time1

Total Time1 30

Course: Dessert

Cuisine: American

Servings:

Calories: 637kcal

225 g Cream cheese full fat (33%+) eg. Philadelphia - no need to bring it to room temp.
75 g Mascarpone full fat (41%+) - no need to bring it to room temp.
45 g Powdered sugar sifted
75 g Peanut butter smooth
½ teaspoon Vanilla extract

Pre-heat oven to 175°C / 347°F and grease an 8-inch / 20 cm Spring form pan.
Cream butter with the two different types of sugar until light and fluffy, then whip in the eggs and milk slowly while the mixer is on. Finally, mix in peanut butter and the vanilla extract.
Sift the flour, salt, baking powder, and baking soda together into the mixture and fold the dry ingredients into the wet ingredients using a rubber spatula just until combined.
Pour the peanut butter cake batter into the prepared pan and smooth the top with an offset spatula.
Bake the cake at 175°C / 347°F for 60 minutes or until a toothpick inserted comes out clean.
Let the cake completely cool before frosting.

Whip the cream cheese, mascarpone, and sifted powdered sugar with an electric hand mixer for a few minutes.
Just before the mixture starts to thicken, add the vanilla extract and smooth peanut butter to the mixture and continue whipping.
When the frosting reaches a fluffy, pipeable consistency, stop right there and do not overmix. If you continue whipping the frosting, it will separate and get runny.

Place the frosting into a piping bag fitted with a round nozzle tip and pipe the frosting on top of the cake. Alternatively, arrange the frosting with the help of a spoon or spatula.
The cake can be served immediately or stored refrigerated for 2-3 days in air-tight container.

Ingredient notes:

Measure your ingredients with a digital scale for accuracy.
For the peanut butter sponge cake, use room-temperature ingredients.
For the peanut butter cream cheese frosting, use high-fat ingredients.
Use only smooth peanut butter, preferably unsweetened. If using sweetened peanut butter, reduce the powdered sugar in the recipe

Baking technique notes:

Make sure you read my Expert Tips section above to maximize your success. A short recipe alone is not enough to cover all the necessary details and science behind baking.
When baking the sponge, be careful not to overbake it. Over-baked sponge cake can become too dry. Only bake it until a toothpick inserted comes out clean, then take the cake out of the oven. Each oven is different, consider using an oven thermometer for accuracy.
Cream cheese frosting is very easy to overwhip. When whipping the frosting, be sure to stop as soon as the mixture has reached a fluffy consistency (this will take 2-3 minutes). It will not get stiffer after this point. In fact, if you overbeat the frosting, it will only get runnier and then break.
If you prefer to make it into a layer cake, cut the sponge into 2 horizontally and double the frosting.