In a medium bowl, mix the sugar and butter with a spoon or hand mixer until thoroughly combined. 

Add the vanilla extract and mix well (optional).

Using a hand mixer, add the flour until well combined. The dough will be crumbly.

Knead dough until it is smooth (use hands if needed). 

Divide the dough into half and shape into a log two inches in diameter. 

Roll out plastic wrap and pour holiday sprinkles in the middle. Take one log and roll in sprinkles, covering all sides. Tightly wrap the dough in plastic wrap.

Wrap the other dough log in plastic wrap without sprinkles. 

Refrigerate the dough for 90 minutes or until firm.

Preheat oven to 350 degrees and line a baking sheet with parchment paper.

Slice the dough into ½-inch thick cookies. Add sprinkles to the plain dough once sliced.

Bake for 12-15 minutes or until the edges are golden brown.

Allow to cool slightly on the baking sheet before serving or moving to a wire rack.