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

Step 2: Cream Butter and Sugar

In a large mixing bowl, cream together the softened butter and granulated sugar until the mixture is light and fluffy. This should take about 2-3 minutes using an electric mixer on medium speed.

Step 3: Add Wet Ingredients

Add the egg and vanilla extract to the creamed mixture, mixing until well combined.

Step 4: Combine Dry Ingredients

In a separate bowl, whisk together the all-purpose flour, baking powder, baking soda, and salt. Gradually add these dry ingredients to the wet mixture, mixing on low speed until fully incorporated.

Step 5: Divide and Color

Divide the dough into four equal portions. Add one package of Jell-O to each portion, mixing well until each dough portion is uniformly colored and flavored.

Step 6: Shape the Cookies

Shape the dough into small balls using your hands, approximately 1 inch in diameter. Roll each ball in extra granulated sugar to coat.

Step 7: Arrange and Flatten

Place the balls on the prepared baking sheets, spacing them about 2 inches apart. Flatten each ball slightly with the bottom of a glass or your fingers.

Step 8: Bake

Bake in the preheated oven for 8-10 minutes. Avoid overbaking as the cookies should remain soft. Remove from the oven and allow them to cool on the baking sheet for a few minutes before transferring to a wire rack to cool completely.