Swedish Shortbread Cookies

In Sweden, these shortbread cookies are traditionally
cut into star shapes and garnished with pearl sugar.

Ingredients:
16 tbsp. unsalted butter
1 cup superfine sugar
2 eggs, separated
2 tsp. vanilla extract
4 cups flour
1 tsp. kosher salt
Pearl sugar, for garnish

Directions:
Combine butter and superfine sugar
in a large bowl and beat,
using a handheld mixer set to medium speed,
until mixture is pale and fluffy, 1–2 minutes.
Add egg yolks and vanilla and beat until smooth.
Add flour and salt and beat until just combined.
Transfer dough to a work surface
and shape into a flat disk;
wrap in plastic wrap and refrigerate for 1 hour.
Heat oven to 350 degrees F.
Transfer dough to a floured work surface and,
using a rolling pin, roll dough to a 1/8" thickness.
Using a 2"-wide star-shaped cookie cutter,
cut out cookies and place them 2" apart
on baking sheets lined with parchment paper.
In a small bowl, whisk egg whites until frothy.
Using a pastry brush, brush egg whites evenly
over cookies; sprinkle cookies with pearl sugar.
Bake cookies, 1 sheet at a time,
until just set, about 10 minutes.
Transfer to a wire rack to let cool completely.