01 - Preheat oven to 350°F (175°C). Grease a standard 12-cup muffin tin or line with paper liners.
02 - Slice each biscuit into six equal pieces using a small knife or kitchen scissors.
03 - In a mixing bowl, combine granulated sugar and ground cinnamon until evenly blended.
04 - Dip each biscuit piece into the melted butter, ensuring full coverage, then roll in the cinnamon sugar mixture.
05 - Gently toss coated biscuit pieces with rainbow sprinkles until thoroughly coated.
06 - Place five to six coated pieces into each prepared muffin cup, distributing evenly.
07 - Bake on the center rack for 18–20 minutes or until biscuits are golden brown and set.
08 - Allow muffins to cool in the tin for five minutes before transferring to a wire rack.
09 - In a clean bowl, whisk together powdered sugar, milk, and vanilla extract until smooth and pourable.
10 - Drizzle glaze over slightly cooled muffins and finish with additional rainbow sprinkles as desired.