01 - In a large bowl, whisk together flour, sugar, baking powder, baking soda, and salt until well blended.
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. Be careful not to overmix; small lumps are acceptable.
04 - Divide the batter evenly between two bowls. Add cocoa powder and red food coloring to one bowl; stir until thoroughly blended to create the red velvet batter. Leave the remaining batter plain for the vanilla portion.
05 - Preheat waffle iron according to manufacturer's instructions. Lightly grease the plates 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 for a marbled effect.
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 while warm. Top with cream cheese glaze, maple syrup, whipped cream, or fresh berries as desired.