01 - Whisk together flour, sugar, baking powder, baking soda, and salt in a large bowl until thoroughly blended.
02 - In a separate bowl, whisk together buttermilk, eggs, melted butter, and vanilla extract until smooth and uniform.
03 - Gently fold the wet mixture into the dry ingredients just until combined. Take care not to overmix to maintain tender texture.
04 - Divide batter evenly between two bowls. Add cocoa powder and red food coloring to one bowl; stir until fully incorporated and color is uniform. Leave second bowl plain for vanilla batter.
05 - Preheat waffle iron according to manufacturer instructions. Lightly grease with oil or nonstick cooking spray.
06 - For each waffle, drop alternating spoonfuls of red velvet and vanilla batters onto center of hot iron. Use chopstick or butter knife to gently swirl batters together for marbled appearance.
07 - Close lid and cook until waffles are golden, crisp, and cooked through, approximately 3 to 5 minutes per batch.
08 - Serve immediately with cream cheese glaze, maple syrup, or fresh fruit as desired.