Small Chocolate Cake (6 Inch)

Make Ahead & Freezing Instructions: The cake can be baked, cooled, and covered tightly at room temperature overnight. Frosted or unfrosted cake can be frozen up to 2–3 months. If desired, see my How to Freeze Cakes post. Thaw cake overnight in the refrigerator and bring to room temperature before decorating/serving. For make-ahead instructions for the chocolate ganache, see step 5 in my chocolate ganache post.
Special Tools (affiliate links): 6×2-inch Cake Pan | Glass Mixing Bowls | Whisk
Cocoa Powder: Use natural cocoa powder, not dutch-process. (See dutch-process vs natural cocoa powder for more information.)
Espresso Powder: Espresso powder will not make the cake taste like coffee. Instead, it deepens the chocolate flavor. It’s optional, but for best taste, I highly recommend it. You can use the same amount of instant coffee (the powder) instead of espresso powder if desired.
Amount of Sugar: I tested this recipe with 6 Tablespoons of sugar and the cake wasn’t as sweet, of course, but it tasted pretty plain. I recommend sticking with 8 Tbsp (1/2 cup). Topping with chocolate ganache definitely balances out the sweetness.
Buttermilk: Buttermilk is required for this recipe. You can make your own DIY version of buttermilk if needed. Add 1/2 teaspoon of white vinegar or lemon juice to a liquid measuring cup. Then add enough whole milk to the same measuring cup until it reaches 1/4 cup. (In a pinch, lower-fat or nondairy milks work for this soured milk, but the cake won’t taste as moist or rich.) Stir it around and let sit for 5 minutes. The homemade “buttermilk” will be somewhat curdled and ready to use in the recipe.
6 Cupcakes: Preheat oven to 350°F (177°C). Line a standard muffin pan with 6 liners. Prepare the batter as directed in step 2 above. Pour or spoon the batter into the liners. Fill each 2/3 full to avoid spilling over the sides or sinking. Bake for 20–22 minutes, or until a toothpick inserted in the center comes out clean. Don’t over-bake, which will dry out the cupcakes. Allow the cupcakes to cool completely before frosting.
Chocolate in Ganache: Ganache will only set if the correct chocolate is used. You can use high-quality chocolate chips if needed (I prefer Ghirardelli semi-sweet chocolate chips), but I recommend using pure chocolate baking bars. You can find them right next to the chocolate chips in the baking aisle. They are sold in 4-ounce (113g) bars. I like Bakers or Ghirardelli brands. You can use other varieties of chocolate too, such as milk chocolate (aka German chocolate), bittersweet, or dark chocolate. If using white chocolate, reduce the cream to 1/3 cup (80ml). White chocolate is softer, so you need less cream.
Dairy-Free Alternative for Heavy Cream in Ganache: Use 1/2 cup full-fat canned coconut milk. Shake it up before opening and measuring. Whisk on the stove as it heats and bring to a simmer.
8-inch Pan or 2-Layer Cake: You can use this cake batter in an 8×2-inch cake pan in step 1. The cake will be thinner and the bake time is about 24–25 minutes, but use a toothpick to test for doneness just as instructed above. I don’t recommend doubling this recipe to make a 2-layer cake because it will be quite thick and taste heavy. Instead, divide the batter between 2 6-inch cake pans (bake time would be shorter) or divide the batter from these chocolate cupcakes in 2 6-inch cake pans. Start checking with a toothpick at 26 minutes.