This is the cake I make for every birthday in my family — kid, adult, grandparent, doesn’t matter. Chocolate cake with buttercream frosting is the birthday cake to end all birthday cakes: two tall layers of impossibly moist chocolate cake (the secret is hot coffee in the batter), sandwiched and topped with thick swirls of classic American vanilla buttercream frosting. 75 minutes start to finish, serves 12, better than any bakery for half the cost.
Fun fact: the addition of hot coffee to chocolate cake batter — popularized by Ina Garten’s “Beatty’s Chocolate Cake” recipe in 2008 — is rooted in food science. Coffee contains compounds that intensify chocolate’s flavor (called “potentiation”), and hot liquid blooms cocoa powder, releasing aromatics. You can’t taste the coffee, but the chocolate flavor doubles. Chocolate cake itself dates to 1764 when Dr. James Baker began commercial cocoa production in Massachusetts.
Why this recipe works
Hot coffee blooms the cocoa. Pouring boiling coffee into the dry cocoa releases chocolate aromatics 10x more powerfully than room-temp liquid. You won’t taste coffee — only deeper chocolate.
Oil instead of butter. Oil stays liquid at fridge temp, keeping the cake moist for days. Butter cakes go dry in 24 hours. This cake tastes fresh on day 4.
Buttercream needs room-temp butter. Cold butter clumps; warm/melted butter makes soupy frosting. 65°F butter that gives slightly when pressed = perfect whipping consistency.
Ingredients
Serves 12 (two 9-inch round layers).
For the chocolate cake
1 3/4 cups all-purpose flour
2 cups granulated sugar
3/4 cup unsweetened cocoa powder (natural, NOT Dutch-processed)
2 tsp baking soda + 1 tsp baking powder + 1 tsp salt
2 large eggs, room temp
1 cup buttermilk, room temp
1/2 cup vegetable oil
2 tsp vanilla extract
1 cup HOT freshly brewed coffee (or hot water + 2 tsp espresso powder)
Heat oven to 350°F. Butter two 9-inch round cake pans, line bottoms with parchment, butter parchment, then dust with cocoa. In a large bowl, whisk flour, sugar, cocoa, baking soda, baking powder, and salt until uniform.
Step 2: Combine wet ingredients
In a separate bowl, whisk eggs, buttermilk, oil, and vanilla until smooth.
Step 3: Mix and add hot coffee
Pour wet ingredients into dry; whisk gently until just combined. Carefully pour in hot coffee while whisking — batter will be VERY thin and that’s correct. Divide evenly between prepared pans.
Step 4: Bake until just set
Bake 30-35 minutes until a toothpick inserted in center comes out with a few moist crumbs (not wet batter, not bone-dry). Tops should spring back when lightly pressed. Cool in pans 10 minutes, then flip onto wire racks. Cool completely (about 1 hour) before frosting.
Step 5: Make the buttercream
Beat softened butter with an electric mixer 3-4 minutes until pale and fluffy. Add powdered sugar 1 cup at a time, beating between additions. Add vanilla, salt, and 4 tbsp cream. Beat 3-4 min on high — frosting should be light, fluffy, and spreadable. Add more cream by the teaspoon if too stiff.
Step 6: Assemble and frost
Level cake tops with a serrated knife if domed. Place first layer on serving plate. Spread 1 1/2 cups buttercream over top. Place second layer on. Apply thin “crumb coat” of frosting all over and refrigerate 15 minutes. Apply final thick layer of frosting, swirl decoratively. Garnish with chocolate shavings.
Nutrition information
Calories: 580 kcal per slice
Protein: 5 g
Carbohydrates: 85 g
Fat: 26 g
Iron: 12% DV (from cocoa)
Sugar: 68 g
Pro tips for bakery-quality cake
Room-temp everything. Cold eggs and buttermilk seize the batter and won’t emulsify properly. Set ingredients on counter 1 hour before baking.
Crumb coat is essential. Thin first layer of frosting traps crumbs; refrigerate 15 min; final coat goes on crumb-free. Bakeries always do this.
Don’t over-bake. Chocolate cake goes from moist to dry in 5 minutes. Pull at 30 min and test — moist crumbs on toothpick = done.
Cake strips for level layers. Wet cake strips (Wilton brand) around the pan edges = perfectly flat tops, no doming, no leveling needed.
Frequently asked questions
Why is my cake dense?
Either cold ingredients (room temp essential), overmixed batter (mix only until just combined), or old leavening (baking powder/soda lose potency after 6 months). Check expiration dates on baking soda.
How long does it keep?
Room temp 3 days in cake dome (buttercream stays soft). Refrigerator 1 week (let slices come to room temp before serving). Cake stays moist longer than most thanks to the oil.
Can I freeze it?
Yes — wrap unfrosted layers in plastic + foil, freeze 3 months. Thaw at room temp before frosting. Frosted cake also freezes 1 month; thaw overnight in fridge then 2 hours on counter.
Is the coffee taste detectable?
No — even sensitive palates can’t detect coffee. It only enhances the chocolate flavor through bloom and depth. Skeptics challenged to find it in blind taste tests have failed. Use decaf if extremely sensitive.
Can I make it as cupcakes?
Yes — fills 24 standard cupcakes. Bake at 350°F for 18-20 min until toothpick comes out clean. Frosting amount stays the same. Pipe with star tip for bakery-style swirls.
What if buttercream is too sweet?
Add 1/2 tsp more salt and increase vanilla to 1 tbsp. Or substitute Swiss meringue buttercream (less sugar, silkier texture). The recipe above is classic American buttercream by design.
