Sparkling Shortbread Cookies

1. Prepare the Butter Mixture

In your stand mixer fitted with a paddle attachment, gently beat together the unsalted butter, granulated sugar, and kosher salt until just smooth.

2. Add Egg Yolks

Introduce the egg yolks into the butter mixture, combining them lightly.

3. Incorporate Flour

Gradually mix in the all-purpose flour on low speed until just incorporated.

4. Chill the Dough

Shape the dough into logs, wrap them in parchment paper, and chill in the refrigerator until firm.

5. Prepare for Baking

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

6. Add Sparkle to Dough Logs

Brush the chilled dough logs with beaten egg white and roll them in decorative sugar.

7. Slice and Bake

Slice the logs into 1/2-inch rounds, arrange on the baking sheet, and bake for 18-22 minutes until golden around the edges.

8. Cool the Cookies

Transfer the baked cookies to a wire rack to cool.