01 -
In a medium bowl, whisk together flour, baking powder, and salt until evenly blended to ensure a tender texture and prevent clumping.
02 -
Using a mixer, beat softened butter and granulated sugar on medium speed until pale and fluffy, approximately 3 to 4 minutes, scraping sides as needed.
03 -
Add egg whites one at a time, beating well after each addition, then blend in Greek yogurt, milk, and vanilla on low speed until just combined.
04 -
Gradually mix in green gel food coloring until the batter reaches a vibrant watermelon rind shade, taking care not to over-color.
05 -
Add the dry ingredients to the wet mixture in two portions, mixing gently on low speed to just combine, preserving fluffiness.
06 -
Preheat oven to 350°F. Line a muffin tin with cupcake liners and fill each two-thirds full with batter. Bake for 16 to 19 minutes until a toothpick comes out clean. Cool completely.
07 -
Beat room-temperature butter until creamy, 2 to 3 minutes. Gradually add powdered sugar, beating until fluffy. Blend in watermelon Kool-Aid powder and pink gel food coloring. Adjust consistency with milk as needed.
08 -
Once cooled, frost cupcakes generously using a piping bag or spatula. Optionally, garnish with mini chocolate chips to resemble watermelon seeds.