Decadent Chocolate Cake with Chocolate Buttercream

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When I set out to open my own pastry shop, I knew that there were a few recipes that had to be absolutely perfect. Obviously, a truly wonderful and decadent chocolate cake was one of them. I’m pretty sure I’ve made every chocolate cake that was on the internet at the time. Some were good, but I really wanted mine to be perfectly moist, have the right amount of chocolate flavor and pair well with any buttercream.

Because this cake uses oil instead of butter, it stays moist for several days. Not that it will last that long. I use this cake as the base for all of my chocolate cakes and they always disappear quickly!

decadent Chocolate Cake

Even if you aren’t a fan of coffee, PLEASE do not skip out on the addition of coffee and espresso powder. They boost the chocolate flavor without making the cake taste like coffee. You can find espresso powder in some specialty kitchen stores. My favorite is this King Arthur Flour brand. If you don’t have a coffee maker, feel free to use instant coffee. Just be sure to use boiling water.

Decadent Chocolate Cake with Chocolate Buttercream

Recipe by Amanda Innes-ShareefCourse: DessertDifficulty: Easy


Prep time


Cooking time





The serving size and calories listed here are for a 9×13 cake with buttercream.


  • All Purpose Flour 240g
    (1 1/2 cups)

  • Sugar 300g
    (1 1/2 cups)

  • Dark cocoa 85g
    (3/4 cup)

  • Espresso Powder 1 tsp

  • Baking Soda 1 1/2 tsp

  • Baking Powder 1 tsp

  • Salt 1 tsp

  • Buttermilk 200g
    (3/4 cup)

  • Vegetable Oil 95g
    (1/2 cup)

  • 2 Eggs

  • Hot Coffee 170g
    (3/4 cup)


  • Preheat oven to 350°. Spray a 9×13 pan. OR spray and parchment three 6″ round cake pans. OR spray and parchment two 8″ round cake pans.
  • Add dry ingredients to medium sized mixing bowl and whisk to ensure all ingredients are combined.
  • In a separate bowl, whisk together vegetable oil, buttermilk and eggs.
  • Add wet ingredients to dry ingredients and beat just until combined.
  • Add HOT coffee and mix again just until combined. Use a spatula to scrape down the sides of the bowl.
  • Bake for 18-22 minutes, or until a toothpick inserted comes out clean.


  • Make sure all of your wet ingredients are room temperature. I like to leave my eggs out overnight and I microwave my buttermilk for about 30-45 seconds before using.
  • You can also make 18 cupcakes with this recipe.

Chocolate buttercream

  • Butter 226g
    (1 cup)

  • Cocoa Powder 75g
    (2/3 cup)

  • Powdered Sugar 345g
    (3 cups)

  • Heavy Cream 45-60g
    (no more than 1/4 cup)

  • Salt 1/4 tsp


  • Beat butter until smooth and creamy.
  • Add powdered sugar and mix on low speed until well combined.
  • Add cocoa powder and salt and continue mixing on low.
  • Add heavy cream, 1 tablespoon at a time, and mix on high speed for 7-8 minutes until light and fluffy.
  • You may not need all of the heavy cream or you may need a little more. It depends on a number of things, including the humidity, temperature of your ingredients, and the type of equipment being used.