Mix the flour, sugar, cocoa powder, baking powder, and salt in medium bowl and then set aside.
Spray the waffle maker with cooking spray while its preheating.
In a medium bowl, beat together eggs, buttermilk, butter, vanilla, and vinegar on low speed until combined.
Add several drops of red food coloring
Pour milk mixture into dry ingredients and mix until combined.
Cook waffles according to your waffle iron and size.