01 - Preheat waffle iron according to manufacturer's instructions.
02 - In a large bowl, whisk together flour, cocoa powder, sugar, baking powder, baking soda, and salt until well incorporated.
03 - In a separate bowl, beat eggs then whisk in milk, melted butter, and vanilla extract until smooth.
04 - Pour wet ingredients into dry ingredients and stir until just combined. Avoid overmixing to prevent tough waffles.
05 - Lightly grease waffle iron. Pour 1/2 to 3/4 cup batter per waffle depending on iron size. Cook until crisp and cooked through, approximately 4 to 6 minutes.
06 - Transfer waffles to serving plates. Top with mixed berries, banana slices, toasted nuts if desired, whipped cream, chocolate syrup drizzle, and powdered sugar dusting. Serve immediately while warm.