1. Preheat your waffle iron according to the manufacturer’s instructions. Lightly grease it with cooking spray or melted butter to prevent sticking.
2. In a large bowl, whisk together the flour, sugar, cocoa powder, baking powder, baking soda, and salt until well combined.
3. In a separate bowl, beat the eggs, then add the buttermilk, melted butter, and vanilla extract. Mix until smooth.
4. Gradually add the wet ingredients to the dry ingredients, stirring gently until just combined. Be careful not to overmix; a few lumps are okay.
5. Divide the batter into two bowls. Add the red food coloring to one bowl and mix until the color is evenly distributed.
6. For each waffle, pour a small amount of red batter into the center of the waffle iron, and then pour a small amount of plain batter on top. Use a toothpick or skewer to gently swirl the batters together, creating a marbled effect.
7. Close the waffle iron and cook the waffles until crisp and golden, about 4-5 minutes or until your waffle iron’s indicator shows they are done.
8. Carefully remove the waffles and keep them warm in a low oven while you cook the remaining batter.

From my experience, patience is key when swirling the batters. It’s a fun, creative process that reminds me of the times I’d spend experimenting in the kitchen with my grandma, each swirl a new adventure.