In a large bowl, sift together the flour, cocoa powder, sugar, baking powder, and salt. Move the dry ingredients to the sides of the bowl to make a well in the middle and pour in the milk, egg, and butter. Use a fork to whisk the egg first, then combine the wet ingredients with the dry to make a batter. Stop mixing when there's no visible dry ingredients.
Add the food coloring and stir until the batter reaches the desired shade of red. Start with 4 drops, and gently fold the color into the batter with a spatula, then add more, one drop at a time. Gel food coloring is more concentrated than liquid, so you'll need to use less.
Cook the pancakes:
Heat a non-stick griddle or large pan over medium heat. Once hot, grease, spray, or melt butter on the hot surface. When using an electric griddle, heat it somewhere between 300 and 325F. Immediately, pour ¼ cup of pancake batter onto the greased pan.
Cook the pancakes for about 2 minutes, until the edges are defined and bubbles form. Flip the pancakes over and cook for another minute on the other side. They're ready when the middles are puffy. Remove them from the pan onto a plate and cook the remaining pancakes. If using butter to grease the pan, rinse or wipe down between batches to avoid burnt butter and dark brown pancakes.
Make the drizzle:
In a medium bowl, mix the powdered sugar with milk until smooth.
Serve:
Serve the pancakes warm and drizzle the sugary glaze lightly over the top.
Notes
Using Pancake Mix: For every 1 cup of pancake mix, add 1 ½ tablespoons of cocoa powder, 1 tablespoon of additional liquid (water for a complete mix or milk for traditional), and 2-3 drops of food coloring. Remember to add the other ingredients listed in the box.
Nutrition information is for pancakes only, without the drizzle.