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