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

Cream softened unsalted butter and granulated sugar in a large mixing bowl for about 2-3 minutes until light and fluffy.

Beat in one large egg until thoroughly incorporated, about 1 minute.

In a separate bowl, whisk together all-purpose flour, baking powder, and salt, then gradually add to the wet mixture.

Divide the dough into 3-4 portions and mix in different Jello flavors to create vibrant colors.

Wrap each portion in plastic wrap and refrigerate for 15-20 minutes.

Roll tablespoon-sized portions into balls and coat in additional granulated sugar.

Flatten each ball slightly and arrange on the baking sheets, spacing about 2 inches apart.

Bake for 8-10 minutes until the edges are set and tops are cracked. Allow to cool for 2 minutes before transferring to a wire rack.