01 - Preheat your 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 combined.
03 - In a separate bowl, beat eggs, then whisk in milk, melted butter, and vanilla extract until smooth.
04 - Pour the wet ingredients into the dry ingredients and stir until just combined; do not overmix as this will toughen the waffles.
05 - Lightly grease the waffle iron. Pour batter into the waffle iron (about 1/2 to 3/4 cup per waffle, depending on size). Cook until crisp and cooked through, about 4–6 minutes.
06 - Transfer waffles to serving plates. Top each waffle with mixed berries, banana slices, nuts (if using), and a dollop of whipped cream. Drizzle with chocolate syrup and dust with powdered sugar if desired. Serve immediately.