This is the cake from the photo: three ultra-moist dark chocolate cake layers, silky caramel peanut butter buttercream, a caramel drizzle, and crunchy chocolate hazelnut truffles on top. The crumb is dark, soft, and fudgy, the frosting is light and nutty, and every slice looks like a bakery window cake. It is a showstopper for birthdays, holidays, or any time you want a serious chocolate cake.
It looks impressive, but it is very doable at home. The cake layers are a one-bowl oil-based chocolate cake, so they stay moist for days. The frosting is a whipped peanut butter caramel buttercream that pipes beautifully and holds up well. Total active time is about 45 minutes.
Ingredients
For the Moist Chocolate Cake Layers – makes three 8-inch layers:
• 2 1/2 cups all-purpose flour
• 1 cup unsweetened cocoa powder, Dutch-process preferred
• 2 cups granulated sugar
• 2 teaspoons baking soda
• 1 teaspoon baking powder
• 1 teaspoon fine salt
• 3 large eggs, room temperature
• 1 cup neutral oil, vegetable or canola
• 1 1/2 cups buttermilk, room temperature
• 2 teaspoons vanilla extract
• 1 cup hot strong coffee or hot water
For the Caramel Peanut Butter Buttercream:
• 1 1/2 cups unsalted butter, softened
• 1 cup creamy peanut butter
• 4 cups powdered sugar, sifted
• 1/3 cup caramel sauce, plus extra for drizzling
• 2 to 4 tablespoons heavy cream
• 1 teaspoon vanilla extract
• 1/4 teaspoon salt
For Decorating:
• 8 to 10 chocolate hazelnut truffles, halved, Ferrero Rocher style
• 1/4 cup caramel sauce, for drizzling
• 2 tablespoons chopped toasted hazelnuts or peanuts
• Chocolate shavings, optional
If you do not have buttermilk, use 1 1/2 cups milk + 1 1/2 tablespoons lemon juice, sit 5 minutes.
Step-by-Step Instructions
1. Bake the Chocolate Cake Layers
Preheat oven to 350°F / 175°C. Grease three 8-inch round cake pans, line bottoms with parchment, grease again.
In a large bowl, whisk flour, cocoa powder, sugar, baking soda, baking powder, and salt.
Add eggs, oil, buttermilk, and vanilla. Whisk until smooth, about 1 minute. Pour in hot coffee. Whisk slowly until combined. The batter will be thin, that is correct, that is what gives you a moist crumb.
Divide evenly between the three pans. Bake 28 to 32 minutes, until a toothpick inserted in the center comes out with moist crumbs, not wet batter.
Cool in pans 10 minutes, then turn out onto wire racks. Cool completely before frosting. Warm cake will melt buttercream.
You can bake the layers a day ahead. Wrap cooled layers tightly in plastic and store at room temperature.
2. Make the Caramel Peanut Butter Buttercream
Beat softened butter and peanut butter together on medium-high speed for 3 minutes, until light and fluffy.
Add powdered sugar 1 cup at a time, beating well between additions. Add caramel sauce, vanilla, and salt. Beat 2 minutes.
Add heavy cream 1 tablespoon at a time until the frosting is smooth, fluffy, and spreadable. It should hold a peak for piping. If it is too soft, chill 15 minutes. If too thick, add another tablespoon of cream.
3. Assemble the Layer Cake
Level cake tops with a serrated knife if domed.
Place one chocolate layer on a cake stand. Spread about 3/4 cup buttercream evenly over the top. Repeat with the second layer and more buttercream.
Place the third layer top-side down for a flat top. Apply a thin crumb coat of buttercream all over the cake. Chill 20 minutes. This locks in crumbs.
Frost the outside with the remaining buttercream, smoothing the sides with an offset spatula. Pipe swirls on top if you want the bakery look from the photo.
4. Decorate
Drizzle caramel sauce over the top swirls, letting it drip down the sides naturally. Top with halved chocolate hazelnut truffles, a sprinkle of chopped toasted hazelnuts, and chocolate shavings.
Chill the cake 30 minutes before slicing for clean layers, just like the slice in the photo.
Storage and Make-Ahead Tips
Room Temperature: Covered, 1 day. The oil-based cake stays soft.
Fridge: Airtight container or cake dome, 5 days. Bring slices to room temperature for 30 minutes before serving for the softest crumb and creamiest frosting.
Freezer: Freeze unfrosted cake layers, double wrapped, for up to 3 months. Thaw at room temperature, still wrapped. Frosted whole cake can be frozen too, freeze uncovered 1 hour to set the frosting, then wrap well. Thaw overnight in the fridge.
Make Ahead: Bake layers 2 days ahead and store wrapped at room temperature. Make buttercream 3 days ahead, refrigerate, then bring to room temperature and re-whip until fluffy before using.
Pro Tips for a Perfect Layer Cake
Use room temperature ingredients: Room temp eggs and buttermilk mix evenly and give a better rise. Cold ingredients make a dense cake.
Do not overbake: Pull the layers when a toothpick has moist crumbs. A clean toothpick means overbaked. Chocolate cake continues cooking from residual heat.
Weigh your pans: For perfectly even layers, weigh the batter as you divide it between pans. About 580g per 8-inch pan.
Chill between steps: A 20-minute crumb coat chill makes final frosting so much easier and cleaner. If your kitchen is warm, chill the buttercream 10 minutes if it gets too soft while piping.
Hot knife for clean slices: Dip a sharp knife in hot water, wipe dry, slice. Clean the knife between cuts. This gives you those perfect bakery slices from the photo.
Variations
Chocolate Hazelnut Cake: Replace peanut butter in the frosting with 1 cup chocolate hazelnut spread. Top with whole Ferrero Rocher, exactly like the photo.
Salted Caramel Chocolate Cake: Use salted caramel sauce in the frosting and drizzle, add a pinch of flaky sea salt on top. Skip the peanut butter, increase butter to 2 cups.
Peanut Butter Cup Cake: Fold 3/4 cup chopped peanut butter cups into the frosting between layers.
Mocha Version: Increase coffee to 1 1/4 cups in the cake batter, add 2 tablespoons instant espresso powder to the buttercream.
Gluten-Free: Use a 1-to-1 gluten-free flour blend with xanthan gum. The oil-based batter adapts very well.
Frequently Asked Questions
Can I make this as a 2-layer 9-inch cake?
Yes. Use two 9-inch pans, bake 30 to 35 minutes. You will have slightly thinner layers and extra frosting, which is never a bad thing.
Why use coffee in chocolate cake?
Coffee deepens chocolate flavor dramatically. You will not taste coffee in the finished cake, just richer chocolate. Hot water works fine if you prefer, but coffee is better.
My buttercream looks curdled, what happened?
Butter was too cold, or you added cold cream. Keep beating, it usually comes together in 2 to 3 minutes. If not, gently warm the bowl over a pot of warm water for 10 seconds, then beat again.
Can I use natural cocoa instead of Dutch-process?
Yes. If using natural cocoa, use 1 1/2 teaspoons baking soda + 1 1/2 teaspoons baking powder to balance the acidity. Dutch-process gives the darker color you see in the photo.
How do I get flat cake layers?
Bake at 350°F, not higher. Use cake strips or wrap damp towels around the pans. And level any dome with a serrated knife before stacking, save the scraps for cake pops.
This chocolate caramel peanut butter layer cake is moist, rich, nutty, and completely bakery-worthy. Three tender chocolate layers, fluffy peanut butter caramel frosting, caramel drizzle, and crunchy chocolate hazelnut truffles on top. Make it for a celebration, and save yourself a big slice first, it goes fast.