Ingredients:

  • 2 cups (250g) all-purpose flour
  • 2 cups (400g) granulated sugar
  • 3/4 cup (75g) unsweetened cocoa powder
  • 2 tsp (10g) baking soda
  • 1 tsp (5g) baking powder
  • 1 tsp (5g) salt
  • 1 cup (240ml) buttermilk, room temperature
  • 1/2 cup (115g) vegetable oil
  • 2 large eggs
  • 1 tsp (5ml) vanilla extract
  • 1 cup (240ml) boiling water
  • 1 jar (225g) marshmallow cream or 2 cups (100g) mini marshmallows
  • 1/2 cup (60g) chopped pecans
  • 1/2 cup (115g) unsalted butter
  • 1/2 cup (120ml) whole milk
  • 1/4 cup (25g) unsweetened cocoa powder
  • 3 cups (600g) powdered sugar
  • 1 tsp (5ml) vanilla extract

Instructions:

  1. In a large bowl, sift together flour, sugar, cocoa, baking soda, baking powder, and salt.
  2. Add buttermilk, oil, eggs, and vanilla to the dry ingredients. Beat on medium speed until combined.
  3. Carefully stir in boiling water by hand until the batter is thin and smooth.
  4. Pour batter into a greased 9x13 inch pan. Bake at 350°F (175°C) for 25–30 minutes until a toothpick comes out with just a few moist crumbs.
  5. While the cake is still warm (about 5-10 minutes out of the oven), spread the marshmallow cream evenly across the top.