Preheat oven to 400°F. Line two sheet pans with parchment paper or grease the pans with a non-stick spray. 

In a medium mixing bowl, whisk together the flour, cornstarch, and baking soda, set the bowl aside.

Add the butter and sugar to the bowl of your mixer. Beat on medium speed for about 4 minutes until the butter is light and fluffy. Turn the speed down to low and add in the eggs one at a time, making sure each egg gets incorporated. Slowly pour the flour mixture into the mixture and blend just until combined. 

Scoop about one tablespoon worth of dough, roll the dough into balls and slightly flatten the balls. 

Pour the sprinkles into a plate. Press the cookies into the sprinkles making sure to coat all sides. 

Stagger the cookies on the sheet pan, making sure you leave a gap between the cookies. 

Bake for 8- 11 minutes until the bottoms are golden brown. Allow them to cool on the pan.