Atomic Cake is Chicago’s famous layered cake made with banana, chocolate, and white cake, fresh fruit, creamy pudding, and whipped topping. This easy homemade version costs about $14.21, making it a budget-friendly way to enjoy this bakery favorite at home.
I love desserts that bring something special to family birthdays and celebrations, and this colorful cake is a fun choice when you want something different from a traditional birthday cake. With 8 kids, it’s always a popular choice.
Why You’ll Love This Recipe!
- A Nostalgic Favorite: This Chicago bakery classic brings a fun touch of tradition to birthdays and special celebrations.
- Something for Everyone: Three different cake flavors give everyone a favorite part to enjoy.
- Eye-Catching Dessert: The colorful layers look impressive when you cut into the cake.
- Great for Celebrations: Its generous size makes it a fun dessert to share with family and friends.
- Less Expensive Than Bakery Cake: Enjoy a bakery-style dessert at home while keeping more money in your budget.
After years of baking desserts for my family, I’ve learned that assembling a tall layer cake is much easier when each layer is level and the fillings are spread evenly. Using boxed cake mixes and instant pudding keeps the preparation simple while giving each layer its own flavor.
You may also like to make Punch Bowl Cake and Hummingbird Cake.
Why is it called the Atomic Cake?
Atomic Cake is a Chicago bakery classic: three cake layers (banana, chocolate and yellow or white) stacked with banana custard and sliced bananas, strawberries, and chocolate fudge, then covered in whipped cream. Because it’s frosted all over, nobody knows what’s inside until you cut it.
It’s credited to baker George Kremm, who created it at Calumet Bakery around the late 1940s or early 1950s — the height of the Atomic Age, which gave it its name. Some Chicago bakeries sell it as a “bomb cake” or “banana split torte.”
Bakery vs. Homemade
A whole Atomic Cake from a Chicago bakery can run $45.50 or more. This homemade version costs about $14.21 in cake mixes, pudding, fruit, and whipped topping. If you bake all six layers, you’ll have extra cake layers to freeze for another dessert.
Ingredients
- Instant Pudding Mixes. One small (3.4-ounce) box each of banana, chocolate, and vanilla, standing in for the bakery’s custard and fudge. You’ll use about [1] cup per layer; the rest makes a great after-school snack.
- Instant Pudding Mixes. Banana, chocolate and vanilla — the shortcut for the bakery’s custard and fudge layers.
- Fresh Bananas and Strawberries. About 3 bananas and 1 cup sliced strawberries. Slice them right before assembling so the bananas don’t brown.
- Whipped Topping. A 16-ounce tub (or two 8-ounce tubs), thawed overnight in the fridge so it spreads without tearing the cake.
How To Make Recipe for Atomic Cake
Step 1. Make each cake layer. Prepare each of the cake mix in a 9 inch round cake pan based on the package instructions for the dry ingredients. Bake in the oven. You only need 1 9 inch round cake for each flavor so you will have leftover batter.
Step 2. Let the cakes cool completely at room temperature. Level the cakes. Use a serrated knife to slice off any domed tops so the layers stack flat and don’t slide. Next, make the puddings. Whisk each pudding mix with 2 cups of cold milk in separate bowls for 2 minutes. Chill 5 minutes until thick.
Step 3. Place the banana cake on a platter. Arrange banana slices in a single layer, then spread with banana pudding, leaving a 1/2-inch border so it doesn’t squeeze out.
Step 4. Add the chocolate cake. Top with sliced strawberries and chocolate pudding.
Step 5. Add the white cake and spread the vanilla pudding on top.
Cover the top and sides with whipped topping. Refrigerate at least 2 hours so the layers set before slicing.
Pro Tips
- Bake the layers ahead. Cold or partly frozen layers are firmer, easier to level, and crumb less when you stack them.
- Slice the bananas last. Cut them right before they go on the cake so they stay bright.
- Cut with a long knife, wiped clean. Use a long serrated knife, wipe it between slices, and lift each piece with a cake server so the layers stay neat.
Variations
- Cake Layers. You can substitute the white cake mix for yellow cake if desired. Yellow or banana cake are both delicious.
- Use all the batter. Each box makes two 9-inch rounds. Bake all six layers, then wrap and freeze the extra three for a second Atomic Cake later — or bake the leftover batter as cupcakes.
- Bakery-style strawberry layer. Spread ½ cup strawberry glaze (near the fresh strawberries in the produce section) over the strawberries for that classic Chicago flavor.
- Chocolate fudge. Swap the chocolate pudding for a thin layer of hot fudge sauce.
FAQ
Yes. Bake the layers up to 2 days ahead and wrap them tightly or freeze them up to 2 months. Assemble the day of or the night before. Slice the bananas right before assembling.
Not making a second Atomic Cake? Cube the extra layers into a Punch Bowl Cake.
Level the cakes, chill the puddings until thick, leave a border around each layer, and refrigerate the cake before slicing.
Yes. Yellow cake works in place of white or banana, and strawberry cake mix is a fun swap for the top layer. Keep one chocolate layer so you still get the color contrast when you slice it.
Freeze the plain cake layers, not the finished cake. Bananas, pudding, and fresh strawberries turn watery and brown after thawing.
Storage
Cover leftovers and refrigerate for up to 2–3 days. It’s safe a little longer, but the bananas start to brown and the cake softens after that.
See How Long Does Cake Last in the Fridge and How Long Does Birthday Cake Last.
Easy Cake Recipes
Get ready to enjoy a great cake when you make this recipe. Please don’t forget to leave a comment and star rating.
Atomic Cake
Ingredients
- 1 box Banana Cake Mix
- 1 box Chocolate Cake Mix
- 1 box White Cake Mix
- Ingredients to prepare the cake mixes based on the package instructions.
- 3 Fresh Bananas sliced
- 4 ounces Fresh Strawberries sliced
- 1 box Instant Banana Pudding Mix 3.4 ounces
- 1 box Instant Chocolate Pudding Mix 3.4 ounces
- 1 box Instant Vanilla Pudding Mix 3.4 ounces
- 6 cups Cold Milk
- 16 ounces Whipped Cream Cool Whip
See how we calculate recipe costs.
Instructions
- Prepare each cake mix in a 9 inch round cake pan based on the package instructions. You only need 1 9 inch round cake for each flavor so you will have leftover batter.
- Let the cakes cool completely at room temperature.
- Then mix each of the pudding mixes with 2 cups of cold milk in a separate mixing bowl and refrigerate for 5 minutes until the pudding is set.
- Once all the ingredients are prepared, it’s time to assemble the cake.
- Level the cakes with a serrated knife.
- Place the round banana cake on a serving plate or cake platter. Arrange the banana slices in an even layer on top of the cake. Spread the banana pudding on top of the bananas in an even layer (you may not need all the pudding).
- Place the chocolate cake on top of the banana pudding. Top with the sliced strawberries and the chocolate pudding.
- Then place the white cake on top of the chocolate pudding and spread the vanilla pudding on top of the white cake.
- Spread the whipped cream on the top and the sides of the cakes.
- Refrigerate at least 2 hours before slicing.
Can you change out the vanilla cake mix to a different flavor?
Jerry – You can try swapping the vanilla cake mix with yellow or banana cake. Hope this helps!