Preheat the oven to 375°. Prepare a 12 cup muffin tin with cupcake liners. Spritz the liners with nonstick cooking spray.
In a large mixing bowl, whisk together the flour, cocoa powder, baking powder, salt, and sugar.
In a different bowl, mix the egg, vegetable oil, and buttermilk until well blended.
Pour the wet ingredients into the bowl with the dry ingredients. Mix just until blended.
Stir in the food coloring until you reach the desired color.
To make the filling: beat together the cream cheese and powdered sugar until fluffy.
Place a small amount of batter into each of the muffin liners. Then, divide the filling into 12 equal portions, placing it in the center over the muffin batter. Over the filling, place the remaining batter, dividing it evenly between the cups and covering the filling as much as possible.
Bake the muffins for 20 minutes or until a toothpick inserted in the center returns clean. Allow the muffins to cool in the muffin tin for five minutes prior to removing the muffins from the muffin tin and cooling on a wire rack.