01 - Whisk together flour, sugar, baking powder, baking soda, and salt in a large bowl until thoroughly combined.
02 - In a separate bowl, whisk buttermilk, eggs, melted butter, and vanilla extract until the mixture is smooth and homogeneous.
03 - Gently fold the wet mixture into the dry ingredients, mixing just until combined. Avoid overmixing to prevent tough waffles.
04 - Divide the batter evenly between two bowls. Add cocoa powder and red food coloring to one bowl and stir until well blended. Leave the second bowl plain for vanilla batter.
05 - Preheat waffle iron according to manufacturer instructions. Lightly grease the surface with oil or nonstick cooking spray.
06 - Spoon alternating dollops of red velvet and vanilla batters onto the center of the hot waffle iron. Use a chopstick or butter knife to gently swirl the batters together for a marbled effect.
07 - Close the lid and cook until waffles are golden brown, crisp, and cooked through, approximately 3 to 5 minutes per batch.
08 - Serve warm with cream cheese glaze, maple syrup, or fresh fruit as desired.