1. Preheat the waffle iron to medium heat and lightly grease the plates with cooking spray or oil.

2. In a large bowl, whisk the melted butter, granulated sugar, and brown sugar until smooth and glossy.

3. Add the eggs one at a time, then whisk in the vanilla extract until the mixture looks shiny.

4. In a separate bowl, whisk together the cocoa powder, flour, baking powder, and salt.

5. Stir the dry ingredients into the wet ingredients just until combined.

6. Fold in the mini chocolate chips gently.

7. Spoon batter into the center of the hot waffle iron, close the lid, and cook for 3 to 5 minutes, or until the edges look set and the steam slows.

8. Let the waffle rest for 30 to 60 seconds before carefully removing it with a silicone spatula.

9. Serve warm with powdered sugar, whipped cream, berries, chocolate sauce, or ice cream.