Preheat the oven to 325°F. Line a 1-inch tall quarter sheet pan with parchment paper and spray thoroughly.
Sift all dry ingredients into a large bowl and whisk until evenly blended.
In a separate bowl, whisk together all wet ingredients until smooth.
Gently melt the butter and set aside.
Pour the wet ingredients over the dry ingredients. Immediately add the apple cider vinegar and whisk until combined.
Add the melted butter and red food coloring, whisking until the batter is smooth and uniform.
Pour batter into the prepared pan and smooth evenly.
Bake for 16 minutes at 325°F. Without opening the oven, reduce temperature to 300°F and bake for an additional 6–8 minutes.
Test for doneness with a toothpick. Cool completely, wrap tightly, and freeze until firm.