Buttermilk Chocolate Sheet Cake in 35 Min

Instructions:

1. Preheat the oven to 350°F (175°C) and line an 18x13 inch rimmed baking sheet with parchment paper.
2. In a large bowl, whisk together the flour, sugar, cocoa powder, baking soda, and salt until no lumps remain.
3. Stir in the melted butter, buttermilk, beaten eggs, and vanilla extract. Whisk until the batter is smooth and mahogany-colored, taking care not to overmix.
4. Pour the batter into the prepared pan and spread it evenly to the edges with a spatula.
5. Bake for 18–22 minutes, or until the edges just begin to pull away from the sides and the center springs back when lightly touched.
6. While the cake is in its final 5 minutes of baking, combine butter, cocoa powder, and whole milk in a saucepan over medium heat.
7. Bring the mixture to a gentle simmer, then remove from heat and whisk in powdered sugar and vanilla extract until glossy and smooth.
8. Pour the frosting immediately over the hot cake, tilting the pan to ensure total coverage.