In a large bowl, whisk together flour, salt, baking powder, and cocoa powder.

In a separate bowl, cream the softened butter with both granulated and brown sugars until light and fluffy.

Mix in the eggs, vanilla extract, and vinegar until fully incorporated.

Gradually add the dry ingredients to the wet mixture, stirring gently until just combined.

Pour in the red food coloring and stir until the dough is an even, vibrant hue.

Cover the dough with plastic wrap and refrigerate for 1 hour.

Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

Scoop about 2 tablespoons of dough and place it on the baking sheet, leaving space between each.

Gently press a small dollop of marshmallow fluff into the center of each dough ball, sealing it with additional dough.

Bake for 12-15 minutes, until edges are set and centers remain soft.

Let cool on the baking sheet for 5 minutes before transferring to a wire rack.

Optional: Drizzle with melted white chocolate before serving.