In a large bowl, cream together butter and sugar with a mixer until light and fluffy. Blend in egg and vanilla.
In a separate bowl, whisk together flour, baking powder, baking soda, and cream of tartar. Gradually add the flour mixture to the wet ingredients. Sprinkle 8 tbsp of jello and drops of food coloring onto the dough and then knead the dough until combined.
Roll dough into 1-inch balls. If desired, roll the balls into the extra jello powder for a sweeter cookie. Place dough onto the baking sheet two inches apart. Flatten the dough with the bottom of the bowl to allow the cookies to cook evenly.
Bake cookies for 8–10 minutes.
Remove cookies from the pan and allow to cool on a wire rack.