01 - Preheat oven to 350°F. Line two baking sheets with parchment paper.
02 - In a medium bowl, whisk together flour, baking soda, baking powder, and salt.
03 - In a large bowl, cream softened butter and granulated sugar until light and fluffy, about 2 minutes.
04 - Add egg and vanilla extract, beating until well combined.
05 - Gradually add dry ingredients to wet ingredients, mixing until just combined.
06 - Divide dough evenly into two bowls. Add one Jello flavor to each bowl (about 3 tablespoons) and knead until color and flavor are incorporated.
07 - Scoop tablespoon of dough, roll into ball, then gently roll in extra granulated sugar.
08 - Place cookies 2 inches apart on prepared baking sheets.
09 - Bake for 8-10 minutes, until edges are set but centers look slightly underbaked.
10 - Let cookies cool on baking sheet for 5 minutes before transferring to wire rack.