Makes 1 cake INGREDIENTS For cake 2 cups all-purpose flour 1 cup cocoa powder 1½ tablespoons baking soda ½ teaspoon salt ½ cup butter, softened 1 cup brown sugar, packed 1 cup sugar 1½ tablespoons vanilla extract 3 eggs 1½ cups buttermilk For frosting 2 cups heavy cream ½ cup confectioners’ sugar 1⁄8 teaspoon salt…