This marble sheet cake recipe is perfect for feeding a crowd. It's a simple and delicious cake that's easy to make. To make the cake, start by creaming butter and sugar together until light and fluffy. Then add eggs, one at a time, followed by vanilla extract. In a separate bowl, whisk together flour, baking powder, and salt. Gradually add the dry ingredients to the wet mixture, alternating with milk. Finally, divide the batter in half and mix cocoa powder into one half. Pour the vanilla and chocolate batter into a greased sheet pan, alternating between the two. Use a knife to swirl the batter together to create a marble effect. Bake for 25-30 minutes at 350°F. Let the cake cool before slicing and serving.
