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

In a large mixing bowl, cream together the softened unsalted butter and granulated sugar until light and fluffy.

Add the egg and beat until fully incorporated.

In a separate bowl, whisk together the flour, baking powder, and salt. Gradually add to the wet mixture.

Divide the dough into portions and mix in Jello gelatin powder into each for color and flavor.

Wrap each portion in plastic wrap and chill in the refrigerator for 15-20 minutes.

Roll the chilled dough into balls, coat in additional sugar, and place on the baking sheets.

Bake for 8-10 minutes, until edges are set and tops are crackled.

Cool on the baking sheet for 2 minutes before transferring to a wire rack to cool completely.