01 -
Preheat oven to 325 degrees F. Line 2 large baking sheets with parchment paper.
02 -
Beat butter and 2/3 cup sugar until combined in a medium bowl using a handheld mixer. Mixture will be slightly gritty.
03 -
Mix in flour until well blended, then add vanilla if using.
04 -
Scoop dough and roll into 1-inch balls. Roll each ball in remaining sugar for light coating.
05 -
Place balls 2 inches apart on baking sheets. Flatten with measuring cup bottom to 3/16 inch thick. Add sprinkles if using and press lightly.
06 -
Bake 14-16 minutes until edges are slightly golden.
07 -
Let cookies rest on baking sheets 10-15 minutes before moving to cooling rack.