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 in 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.
Notes
This cake made quite a bit of batter (more than I needed for the loaf pan for the Batman cake), so I used the extra to make a Naked Marionberry Cake!