Preheat oven to 350°F / 180°C (160° fan-assisted) and grease and line two 9-inch cake pans.

Sift the dry ingredients (except the espresso powder) into a large bowl and mix together.

2 cups All-purpose Flour,2 cups White Sugar,2 teaspoon Baking Powder,½ teaspoon Salt,½ cup Dutch Processed Cocoa Powder,½ teaspoon Baking Soda

Stir the wet ingredients (except the hot water) together in a separate bowl until combined, then pour them into the dry ingredients and whisk gently until combined and free from lumps. Make sure to scrape down the bottom of the bowl.

You can use a stand mixer for this if you want, but it's very easy to do with just a bowl and a hand whisk.

2 Large Eggs,½ cup Vegetable Oil,½ cup Milk,1 teaspoon Vanilla Extract

Stir the espresso powder into a cup of recently boiled water, then add to the cake batter and mix it in. The batter will be VERY runny, don't worry, this is how it's supposed to be!

3 tablespoon Espresso Powder,1 cup Hot Water

Divide cake batter evenly between cake pans and bake for 30 - 40 minutes, or until a skewer inserted into the middle of the cake comes out clean.

Bake time may vary depending on your oven so always test with a skewer before taking out of the oven.

Whip butter with a whisk attachment on high speed for 5 full minutes until pale and creamy.

Make sure to pause periodically to scrape down the sides of the bowl.

3 sticks Unsalted Butter

Turn the mixer down to medium-high speed and drizzle in the condensed milk very slowly and gradually, a little at a time, whipping in in between additions.

It is important not to add the condensed milk too quickly or it won't emulsify and the buttercream will split.

21 oz Sweetened Condensed Milk

Add the vanilla and salt and whip on high speed for a minute. The frosting should be smooth, thick and glossy.

½ teaspoon Salt,1 teaspoon Vanilla Extract

Mix the espresso powder in 1 tablespoon of hot water and add it to the buttercream, whip until combined.

2 tablespoon Espresso Powder

Check my Russian Buttercream recipe post for more details on this buttercream and a troubleshooting guide.

Once the chocolate cakes have completely cooled, use a cake leeler or serrated knife to cut off the tops to make them level.

If you'd like four thinner cake layers like I have in the pictures, slice each cake in half. You can also just keep it as two thicker layers.

Put one layer of your cake onto a cake plate or board and add an even layer of coffee buttercream, then add the next layer and repeat until all your layers are used.

Cover the cake with remaining buttercream and decorate as desired.