Chocolate Cake With Mint Buttercream

What You’ll Need

These notes will help you understand what each ingredient does in this recipe. or options for substitutions. Scroll down to the printable recipe card to find the exact ingredient quantities and recipe instructions.

Chocolate Cake:

• Butter – Use unsalted butter to grease the pan.
• Flour – All-purpose flour provides the structure.
• Sugar – Granulated white sugar adds sweet flavor and contributes to the overall moistness of the cake.
• Cocoa powder – I use natural unsweetened cocoa powder. For darker chocolate depth, you could substitute it with Dutch processed cocoa (or mix half and half).
• Baking powder and baking soda – Both offer rise and tenderness, while baking soda also neutralizes the acid in cocoa powder to eliminate any bitterness.
• Espresso powder – I like adding this to chocolate baked goods, such as these Nutella Cheesecake Bars, as it boosts the chocolate flavor. This is not the same as instant coffee; espresso powder is actually made by drying brewed espresso, so it’s more concentrated in flavor.
• Salt – I use Morton kosher salt. This balances the chocolate flavor.
• Buttermilk – Use store-bought buttermilk, which is thicker than making your own DIY version with milk and vinegar or lemon juice.
• Vegetable oil – Cocoa powder can make cakes dry, so the added moisture from the oil’s fat balances this. You could use another neutral oil you like to use in baking.
• Eggs – These add more moisture, plus rich flavor. Let these come to room temperature.
• Vanilla extract – Use pure vanilla extract for the very best flavor (not imitation vanilla).
• Coffee – Freshly brewed hot coffee intensifies the chocolate flavor as discussed above, and it also reacts with the baking soda to make the cake light and airy.

Mint Chocolate Chip Buttercream:

• Butter – Unsalted butter provides the creamy, fluffy base. Soften it to room temperature.
• Powdered sugar – Also known as confectioners’ sugar, this finely ground sugar adds sweet flavor that incorporates smoothly.
• Salt – Use kosher salt here, or a fine salt. This helps balance the sweetness.
• Half and half – This offers the right consistency to make the frosting smooth and spreadable.
• Mint extract – Take care to use mint extract, not peppermint extract. The goal is mint chocolate chip ice cream flavor here, not a peppermint candy cane.
• Vanilla extract – This adds a little depth, to keep the mint frosting from being one-dimensional.
• Green food coloring – I use a little bit of Americolor Leaf Green #111. Added coloring is optional. You could also use a different green color.
• Chocolate – Chop it up small, for even distribution.

How to Make Chocolate Cake With Mint Buttercream

If you’d like, make the cake a day ahead of time and store it covered at room temperature before frosting it.

• Prepare the pan. If you plan to remove the cake from the pan before serving, butter a 9×13 pan, line it with parchment paper, then butter the paper and dust with flour. Otherwise, just butter the pan and serve straight from the pan. Preheat the oven to 350°F.
• Mix the dry ingredients. Add the dry ingredients to the bowl of a stand mixer and mix on low speed to combine.

• Add wet ingredients. Mix in the buttermilk, oil, eggs, and vanilla on medium speed until combined. Slowly mix in the coffee, then beat on high for a minute.
• Bake. Pour the batter into the prepared pan and bake for 40 minutes, or until a toothpick comes out clean. Cool on a wire rack for 15 minutes before inverting onto a platter (or cool completely in the pan if you plan on serving from there).

• Make the mint buttercream. Beat the butter in a stand mixer until very light and fluffy. Mix in the powdered sugar and salt and incorporate on low speed, then mix in the half-and-half and extracts. Beat on medium-high until light and fluffy, then mix in the food coloring if you’re using it. 
• Add chocolate. Fold the chopped chocolate into the frosting.

• Frost the cake. Fold the chopped chocolate into the frosting and spread over the cooled cake.
• Serve. Slice the cake. Garnish with additional chopped chocolate if desired. And serve.

How to Store

• Refrigerator: Although you can store this cake at cool room temperature for up to a day, because it has a buttercream frosting, it should be refrigerated for longer storage. Cover and refrigerate for up to 5 days. Serve cold or bring to room temperature before serving. 
• Freezer: To freeze this chocolate cake with mint buttercream, transfer it to an airtight container. Store for up to 3 months and thaw in the fridge before serving.