Ingredients:

  • 225g Unsalted butter, melted
  • 45g Unsweetened cocoa powder, sifted
  • 400g Granulated sugar
  • 4 Large eggs, room temperature
  • 10ml Vanilla extract
  • 190g All purpose flour
  • 3g Salt
  • 300g Mini marshmallows
  • 115g Unsalted butter (for frosting)
  • 80ml Whole milk
  • 25g Unsweetened cocoa powder (for frosting)
  • 375g Powdered sugar, sifted
  • 125g Chopped pecans, toasted

Instructions:

  1. Heat your oven to 180°C (350°F) and grease your 9x13 pan thoroughly. Note: Greasing with butter and a dusting of cocoa powder prevents sticking better than flour.
  2. Combine 225g melted butter with 45g sifted cocoa powder in a large bowl. Whisk until the mixture is glossy and smooth.
  3. Stir in 400g granulated sugar. The mixture will look gritty, which is normal.
  4. Add 4 eggs one at a time, whisking well after each. Wait until each egg is fully absorbed before adding the next.
  5. Fold in 10ml vanilla, 190g flour, and 3g salt. Stop as soon as the last white streak of flour disappears.
  6. Pour into the pan and bake for 30-35 minutes until the center is set but still slightly soft.
  7. Remove the cake and immediately dump 300g mini marshmallows over the hot surface. Return to the oven for 2-3 minutes until they begin to slump.
  8. While the cake cools slightly, melt 115g butter with 80ml milk and 25g cocoa in a saucepan over medium heat. Bring to a gentle simmer while whisking.
  9. Remove from heat and whisk in 375g powdered sugar and 125g pecans. Whisk vigorously until the glaze is silky and free of lumps.
  10. Pour the warm frosting over the marshmallows, spreading gently to the edges. Let it sit for at least 30 minutes to firm up.