01 -
Cream the butter, sugar, and brown sugar together until light and fluffy (2-4 minutes).
02 -
Add the egg and vanilla extract, mixing thoroughly until combined.
03 -
In a separate bowl, whisk together the flour, salt, corn starch, and baking soda.
04 -
Slowly combine the dry ingredients with the wet mixture until a dough forms.
05 -
Gently fold in the rainbow sprinkles.
06 -
Roll the dough into 1-1.5 inch balls and chill for 15-30 minutes.
07 -
Preheat the oven to 350°F (175°C) while the dough chills.
08 -
Place the chilled dough balls on a baking sheet and bake for 9-11 minutes, or until the edges are set but the centers remain soft.
09 -
Cool the cookies completely on a rack before serving.