In a small sauce pot set over low heat, combine the milk and butter and cook until the butter has melted and the mixture is warmed to just below 110°F.
Stir in 1 tablespoon sugar and the yeast then set the mixture aside for 5 minutes.
In a stand mixer fitted with the dough hook attachment, combine the flour, cocoa powder, salt and remaining 1/2 cup sugar.
Add the yeast mixture and eggs to the stand mixer and beat for 2 minutes.
Add red food coloring until the dough reaches your desired color then continue beating for 6 minutes until the dough is combined. (It will be tacky. If it's too tacky, or you're in a humid environment, add 1 tablespoon of flour at a time until the mixture reaches a smooth consistency.)
Grease a large bowl with cooking spray. Transfer the dough into the bowl and cover it with plastic wrap. Store the dough in a warm, dark place until it doubles in size, about 2 hours.
Grease a 13x9-inch baking pan with cooking spray.
Lightly flour your work surface then roll the dough into a rectangle that's 1/4-inch thick and measures about 12x18 inches.