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chocolate snack cake

Dark Chocolate Birthday Snack Cake

  • Author: Elizabeth Buuck
  • Prep Time: 15 min
  • Cook Time: 30 min
  • Total Time: 45 minutes
  • Yield: 16 small slices or 9 large slices 1x


Rich dark chocolate cake topped with fluffy chocolate American buttercream and rainbow sprinkles



For the Dark Chocolate Cake

  • 1 1/2 C All Purpose Flour
  • 1 C Granulated Sugar
  • 1/4 C + 2 TBSP Dark Cocoa Powder
  • 1 tsp Baking Soda
  • 1/2 tsp Baking Powder
  • 1/2 tsp Salt
  • 1/2 C Buttermilk, at room temperature
  • 1/4 C Vegetable Oil
  • 1 Lg Egg + 1 Egg Yolk, at room temperature
  • 2 tsp Pure Vanilla Extract
  • 1/2 C Hot Coffee

For the Chocolate American Buttercream

  • 3/4 C Unsalted Butter, at room temperature (1 1/2 Sticks)
  • 1/2 tsp Salt
  • 1 tsp Pure Vanilla Extract
  • 4 C Powdered Sugar
  • 1/2 C Cocoa Powder
  • 24 TBSP Heavy Cream, at room temperature


For the Dark Chocolate Cake

  • Preheat the oven to 350 and line a 9X9 pan with parchment.
  • In a large bowl, whisk together the flour, sugar, cocoa powder, baking soda, baking powder, and salt.
  • Whisk in the buttermilk and oil. 
  • Whisk in the egg, egg yolk, and vanilla.
  • While continuing to whisk, slowly pour in the hot coffee. Whisk until well combined with no chunks of flour remaining.
  • Pour into prepared pan and bake at 350 for 28-30 minutes. Let cool completely.

For the Chocolate American Buttercream

  • In the bowl of a stand mixer with the paddle attachment, beat the butter for 5-7 minutes, scraping down the bowl as needed. 
  • Add the salt and vanilla. Mix to combine.
  • Add the powdered sugar 2 C at a time, mixing for 3 minutes after each addition,
  • Add the cocoa powder and mix until well combined, scraping down the bowl as needed.
  • Pour in the heavy cream 1 TBSP at a time until you reach your desired consistency.
  • Spread evenly onto chocolate cake using an offset spatula, then use the back of a spoon to create swirls in the frosting. Top with rainbow sprinkles.


Cake will keep at room temperature for up to 2 days or in the fridge for up to 1 week.

Keywords: small batch chocolate cake, one bowl chocolate cake, chocolate birthday snack cake