Cream together the softened butter and powdered sugar using a spatula until light and fluffy.

Add the egg yolk and vanilla extract, mixing until well combined.

Sift in the all-purpose flour and stir until a soft dough forms.

Wrap the dough in plastic wrap and chill in the refrigerator for 20 minutes.

Divide the dough into two sections and roll each into a log about 4 inches long and 1 inch thick.

Wrap the logs separately in plastic wrap and freeze for 45 minutes.

Preheat the oven to 356°F and line a baking sheet with parchment paper.

Unwrap the chilled dough, roll in granulated sugar to coat evenly, and slice into rounds roughly 3/8 inch thick.

Arrange the slices on the baking sheet and bake for 15 to 18 minutes until lightly golden.

Cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.