This atomic cake Chicago recipe is a colorful three-layer cake with a creamy frosting, inspired by one of the South Side’s best-known bakery desserts. The real atomic cake is a tall mix of banana, yellow and chocolate layers with fillings, finished with whipped cream. This version is a simpler, brighter take that you can bake at home in about an hour, with one vanilla batter divided and tinted into three colors.
A note before you start: if you want the traditional bakery cake, with banana cream and fudge between flavored layers, this is not an exact copy of it. The history section below explains how the classic is built, so you can decide which one you want to make. If you want the layered version with chocolate, banana and white cake, see our atomic cake recipe.
What Is Chicago Atomic Cake?
Atomic cake is a Chicago South Side bakery tradition that dates to around the 1950s. It is usually described as three kinds of cake stacked in one: banana cake with a banana or custard-style cream, yellow cake with a strawberry glaze, and chocolate cake with fudge or ganache, all covered in whipped cream. Different bakeries change the order and the fillings, and some sell it under other names, such as bomb cake or banana split torte.
Who invented it is debated. A baker named George Kremm is often credited, and the cake is linked to Calumet Bakery and his own Liberty Bakery. The name is generally tied to the Atomic Age, though even that link is not certain. If you want the full story, Chicago’s WTTW has a good write-up on the history of the atomic cake, and Tasting Table explains how it became Chicago’s birthday cake.
How This Atomic Cake Chicago Recipe Differs From the Classic
- Layers: the classic uses three different cake flavors. This recipe uses one vanilla batter, colored three ways.
- Fillings: the classic has fruit and cream or custard fillings. This version uses a cream-and-butter frosting between the layers, and you can add jam or mousse if you like.
- Effort: the bakery cake is labor-intensive and usually sold whole. This one is aimed at home bakers and takes far less time.
Atomic Cake Chicago Recipe Ingredients
For the cake
- 2½ cups all-purpose flour
- 1½ cups granulated sugar
- 1 cup unsalted butter, softened
- 4 large eggs
- 1 teaspoon vanilla extract
- 1½ teaspoons baking powder
- ½ teaspoon salt
- ½ cup whole milk
For the frosting
- 1 cup heavy cream
- 2 cups powdered sugar
- ½ cup butter, softened
- 1 tablespoon food coloring, in the colors of your choice (gel coloring gives the brightest results)
How to Make the Atomic Cake Chicago Recipe
- Prepare the pans. Heat the oven to 350°F (175°C). Grease and flour three round cake pans (8 or 9 inches).
- Cream the butter and sugar until light and fluffy. Add the eggs one at a time, mixing well after each, then stir in the vanilla.
- Mix the dry ingredients. In a separate bowl, whisk the flour, baking powder and salt.
- Combine. Add the dry ingredients to the butter mixture in additions, alternating with the milk, and mix until just combined.
- Color the batter. Divide the batter into three equal portions and stir a few drops of food coloring into each.
- Bake. Pour each color into its own pan and bake for 20 to 25 minutes, until a toothpick in the center comes out clean.
- Cool. Let the layers rest in the pans for 10 minutes, then turn them out onto a wire rack and cool completely.
- Make the frosting. Whip the heavy cream, butter and powdered sugar until smooth. Divide into three portions and tint them to match the layers.
- Assemble. Spread frosting between the layers and over the top and sides. Decorate with piping or extra frosting.
Tips for a Great Atomic Cake
- Use room-temperature butter and eggs for a smooth batter.
- Do not overmix. Stop as soon as the flour disappears, or the cake turns dense.
- Use gel food coloring and stir it in gently, so the batter keeps its lift.
- Weigh the flour if you can, or spoon it into the cup and level it, rather than scooping.
- Start checking at 20 minutes. Overbaked layers dry out.
- Cool the layers completely before frosting, or the frosting will melt and slide.
- Apply a thin crumb coat first, chill it briefly, then add the final layer of frosting.
Variations
- Make it closer to the classic: use banana, yellow and chocolate cakes in place of the tinted layers, and add sliced bananas, strawberries or fudge between them.
- Fillings: lemon curd, strawberry jam, chocolate mousse or ganache between the layers.
- Frosting: chocolate or cream cheese frosting works in place of the cream-and-butter frosting.
- No food coloring: skip it for a plain, pale layer cake.
What to Serve With Atomic Cake
Vanilla ice cream, fresh fruit and hot coffee or tea all work. For a bigger spread, serve it alongside our Hawaiian carrot pineapple cake or pecan pie dump cake.
How to Store Atomic Cake
- Refrigerator: because the frosting contains heavy cream, keep the frosted cake covered in the fridge for up to 3 to 4 days.
- Unfrosted layers: keep them wrapped in the fridge for up to 2 days before assembling.
- Freezer: wrap unfrosted layers individually in plastic wrap and freeze for up to 2 months. Thaw in the refrigerator overnight, then frost.
- Dry layers: brush them lightly with simple syrup (equal parts sugar and water) if they dry out in storage.
Atomic Cake Chicago Recipe Card
Atomic Cake Chicago Recipe
Ingredients
Equipment
Method
- Preheat the oven to 350°F (175°C). Grease and flour your cake pans.
- Make the cake batter: In a large mixing bowl, cream together the butter and sugar until fluffy. Add eggs one at a time, mixing well after each addition. Stir in vanilla extract.
- Mix the dry ingredients: In a separate bowl, whisk together the flour, baking powder, and salt. Slowly add the dry ingredients to the wet mixture, alternating with milk. Mix until combined.
- Divide and color the batter: Divide the batter into three equal portions. Add a few drops of food coloring to each portion and stir to incorporate, creating colorful layers.
- Bake the layers: Pour each colored batter into its own cake pan and bake for 20-25 minutes, or until a toothpick inserted into the center comes out clean.
- Cool the cakes: Let the cakes cool in the pans for 10 minutes before transferring them to a wire rack to cool completely.
- Make the frosting: Whip the heavy cream, butter, and powdered sugar until smooth. Divide the frosting into three portions and color them to match the cake layers.
- Assemble the cake: Once the layers are cooled, spread frosting between each layer and on the top and sides of the cake. Decorate as desired with piping or additional frosting details.
Notes
Atomic Cake Chicago Recipe FAQs
Is this the traditional Chicago atomic cake?
No. It is a simplified, colorful layer cake inspired by it. The traditional cake uses banana, yellow and chocolate layers with fillings and whipped cream.
Can I make it ahead?
Yes. Bake the layers up to 2 days ahead and refrigerate them wrapped, or freeze them for longer. Frost close to serving.
Can I skip the food coloring?
Yes. You will still have a three-layer vanilla cake.
What if I only have one or two pans?
Bake the layers in batches. Keep the leftover batter in a bowl, covered, and bake the next layer once a pan is cool and ready to reuse.
Can I use a different frosting?
Yes. Chocolate, cream cheese or plain whipped cream frosting all work.
Can I freeze the finished cake?
Freezing the unfrosted layers works best. Frosting can turn soggy after thawing.
