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

Cream softened butter and granulated sugar in a mixing bowl until light and fluffy, about 3-5 minutes.

Add the room temperature egg and blend until incorporated, about 1-2 minutes.

In a separate bowl, whisk together the all-purpose flour, baking powder, and salt for 1-2 minutes.

Gradually add the dry ingredients to the wet batter, stirring gently until just combined, about 1-2 minutes.

Divide the dough into portions based on Jello flavors, mixing the chosen Jello mix into each.

Roll the dough into 1-inch balls, place them on the baking sheet, and lightly flatten each ball.

Bake in the preheated oven for 8-10 minutes until edges are set, but centers are soft.

Cool on the baking sheet for a few minutes before transferring to a wire rack.