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 fully incorporated.
03 - Gently fold the wet mixture into the dry ingredients just until combined. Take care not to overmix as this will result in tough waffles.
04 - Divide the batter evenly between two bowls. To one bowl, add cocoa powder and red food coloring, stirring until well blended to create the red velvet batter. Leave the remaining bowl as plain vanilla batter.
05 - Preheat waffle iron according to manufacturer instructions. Lightly grease the cooking surfaces with oil or nonstick cooking spray.
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, creating a marbled pattern.
07 - Close the lid and cook until waffles are golden brown, crisp, and cooked through, approximately 3 to 5 minutes per batch depending on your waffle iron.
08 - Serve waffles warm with cream cheese glaze, maple syrup, or fresh fruit as desired.