Preheat waffle iron according to the manufacturer’s directions. In a medium bowl, whisk together the flour, sugar, cocoa powder, baking powder, salt and baking soda.

In another bowl, beat together the eggs and melted butter and vanilla, and then add the buttermilk. Add the wet ingredients to the dry and then stir in the chocolate chips just until combined. Allow to rest for 5 minutes.

Ladle the recommended amount of waffle batter onto the center of the iron. Most round waffle makers require about 3/4 cup of batter. Cook until waffle is crispy on both sides and is easily removed from iron. Serve immediately or keep warm in a 200° oven until ready to serve.