Preheat oven to 350°F and prepare baking pan with nonstick spray or butter and parchment.
Add cake flour, baking soda, baking powder, and salt to a bowl and stir until combined. In another bowl stir cocoa powder with the boiling water and mix together. Add black gel coloring and set aside to cool.
In a mixer add butter, vanilla, and sugar and cream together. Add eggs one at a time, fully mixing in after each one.
Add ½ of the dry mixture to butter mixture and combine then add ½ of the sour cream and combine. Repeat until all ingredients are added and mixed in. Then, add cocoa and mix until fully incorporated.
Add batter to the prepared baking dish and bake for 30 minutes or until a toothpick is clean. After the cake has fully cooled, remove it from the baking pan and cut out bats using a cookie cutter.
Pound Cake for Batman Cake
Preheat oven to 350°F and prepare a rectangle baking pan (loaf pan) with non-stick spray or butter and parchment paper.
In a mixing bowl add the flour, baking powder, and salt and mix together until combined.
In a stand mixer or a separate bowl, cream together butter and sugar until nice and fluffy.
Add vanilla and mix in completely. Add eggs one at a time, fully mixing in after each one.
Add ⅓ of the dry mixture to the butter mixture and combine then add ⅓ milk and combine. Repeat until all ingredients are added and mixed in. Add gel food coloring and mix until fully combined.
Add a little batter to the bottom of the rectangle baking pan, no more than ½ inch.
Take bat cutouts and place them upside down in a line along the top of the batter in the pan (put them upside down so when you flip your cake after baking they are right side up).
Carefully add the rest of the cake batter around the bats to fully cover. Place the baking pan in the oven and bake for 45 minutes.