• Preheat oven to 350 degrees. Spray a standard bundt pan with cooking spray and set aside.

Chocolate/Black Cake

• Whisk together the flour, sugar, cocoa powder, baking soda, baking powder and salt.
• With a hand or stand mixer, beat together the buttermilk, Guinness beer, oil, eggs, vanilla and black food coloring on low setting.
• Add the flour mixture to the buttermilk mixture and beat until combined, then beat the cake batter for 4 minutes on medium speed.

Vanilla/Orange Cake

• Beat the granulated sugar and butter with a hand or stand mixer at medium high speed until well blended.
• Change the speed to low and add the egg, milk and vanilla. Change back to medium speed and mix well.
• Whisk together the flour, baking powder and salt and add to the butter mixture. Beat batter for about 1 minute until smooth. Add the orange gel food color and mix again until well blended.

Cake Assembly

• Using two muffin scoops, alternate scooping the chocolate/black cake batter and the vanilla/orange cake batter into the prepared bundt pan until all the batter is gone.
• Tap the pan on the counter to make sure there are no bubbles.
• Bake the cake for 35 - 40 minutes, or until the cake bounces back when lightly touched.
• Allow the cake to cool in the pan for about 20 minutes. Invert the pan onto a cooling rack and allow the cake to continue cooling before serving.