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 on 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 small bowl. 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.
Remove and enjoy!
Notes
Don’t over bake the cookies. The bottoms should be lightly brown. If they seem slightly underdone on top that’s ok, they will continue to cook a little longer while they cool on the pan.
Be sure to measure the flour using the spoon and level method. Too much flour and the cookies will not turn out right.
Roll the cookies in sprinkles right after forming them so the sprinkles stick. If you wait too long they won’t stick as well. Rolling the dough in your hands heats up the outside slightly and helps the sprinkles stick.
To make sure the cookies bake evenly, use an ice cream scoop so all the balls of dough are the same size.
Make sure your butter is softened and your eggs are room temperature before mixing.