Peppermint Chocolate Cake

Marbled cakes look very attractive and adds a more elegant touch to either a bundt cake or tube cake. This cake is fun to make, but requires some time to prepare and bake. I would not recommend making this cake if you are in a rush. It is a very minty cake, with faint traces of the rum and chocolate flavors. The texture is slightly crunchy on the exterior, but moist and soft inside. Serves 16-32 depending on how you slice it.
Ingredients:
2 Cups granulated sugar
1/4 Cup unsweetened cocoa powder
1 Cup (2 sticks) unsalted butter, softened
4 Large eggs, at room temperature
3 1/2 Cups sifted cake flour
3 teaspoons baking powder
1/2 teaspoon table salt
1 Cup milk, at room temperature
2 teaspoons peppermint flavoring or extract
1/8 teaspoon green gel food coloring, or 1/2 teaspoon liquid food coloring
2 teaspoons rum, or rum extract

1. Center an oven rack and preheat the oven to 350 degrees F. Grease either a 12-cup Bundt cake or 10-inch tube pan with nonstick vegetable spray. In a small bowl, combine 1/2 cup of the sugar and all of the cocoa; set aside. In a medium bowl, dry whisk the flour, baking powder, and salt; set aside.
2. In a large bowl, cream the butter on medium speed, gradually adding the remaining amount 1 1/2 cups of sugar for about 3 minutes. Continue on medium speed adding each egg one at a time, beating well after each addition.
3. On low speed, add 1 cup of the flour mixture, beat, then add 1/3 cup of milk and beat again. Repeat until all of the flour mixture and milk are blended into the batter. 
4. Pour half of the batter into the flour mixture's bowl, and add the peppermint extract and food coloring. Stir until the green food coloring is completely incorporated.
5. With the remaining batter, beat in the rum and cocoa&sugar mixture until combined, 1-2 minutes on medium speed.
6. Pour 2/3 of the green batter into the bottom of the cake pan, then pour in all of the chocolate batter over the green batter. Layer the remaining green batter over the chocolate batter. Take a small spatula or plastic and cut through the middle of the batter ring to the bottom of the pan. Bring the spatula toward you and then up toward the side of the pan. Rotate the cake pan with your other pan and repeat. You'll do 2 rotations total, and no more.
7. Bake 45-60 minutes, or until a toothpick inserted comes out clean. Let cool on a wire cake rack for 15-30 minutes in the pan, then unmold onto the cake rack and cool completely for 2 hours. Transfer to a serving plate.

From: All Cakes Considered by Melissa Gray