Preheat the oven: Set your oven to 350°F (175°C) and line baking sheets with parchment paper.
Cream butter and sugar: Beat softened butter and sugar together for about 2 minutes until light and fluffy.
Mix in wet ingredients: Add the egg and vanilla extract, beating until smooth and well combined.
Combine dry ingredients: Whisk flour, baking powder, baking soda, and salt in a separate bowl, then gradually mix into the wet ingredients to form a soft dough.
Divide and add flavors: Split the dough into four equal parts. Knead a different Jell-O flavor into each portion until evenly colored and fragrant.
Shape and coat: Roll the dough into 1-inch balls, then coat each in granulated sugar for a crisp exterior.
Bake: Arrange cookies on the prepared baking sheets, leaving space between them. Bake for 8-10 minutes until the edges are set but not browned.