Rainbow Marble Cake with Homemade Buttercream Frosting - dgratis.info

Ingredients

• 3 cups all-purpose flour
• 3 cups granulated sugar
• 2 1/2 tsp baking powder
• 1 tsp salt
• 1 cup unsalted butter, room temperature (2 sticks)
• 2 tsp vanilla extract
• 1 cup egg whites (about 7 egg whites)
• 1 1/2 cups buttermilk, room temperature
• 1/8 cup vegetable oil
• Gel food coloring (purple, blue, green, yellow, orange, red)
• 3 cups unsalted butter, room temperature
• 11 cups powdered sugar
• 1/3 cup heavy cream (or whipping cream)
• 1 1/2 Tbsp vanilla extract