01 -
Place softened butter and granulated sugar in the bowl of a stand mixer. Using the paddle attachment, beat on medium speed until the mixture is light and creamy, about 3 to 4 minutes. Add the egg and vanilla extract, mixing until fully incorporated; scrape down the sides as needed.
02 -
In a separate medium bowl, whisk together the all-purpose flour, kosher salt, and baking soda. With the mixer on low speed, gradually add the dry mixture to the creamed mixture. Blend until a cohesive dough forms. Remove the dough from the bowl and divide it into three equal parts.
03 -
Roll each dough portion between two sheets of parchment paper to form a 7-inch square. Refrigerate the squares for 15 minutes with the parchment still attached.
04 -
Stack the dough squares on a new piece of parchment paper—layering red, green, and plain dough if coloring, or as preferred. Cover with another sheet of parchment, then use a rolling pin to flatten into a 12x8-inch rectangle. Remove the top parchment, and starting from a long side, roll the dough tightly into a log. Wrap in parchment and freeze for one hour.
05 -
Preheat the oven to 350°F (177°C). Line two baking sheets with parchment paper.
06 -
With a serrated knife, cut the chilled dough log into 1/3-inch thick rounds. Roll the edge of each round in red sanding sugar, then set cookies 1 inch apart on the prepared baking sheets.
07 -
Bake for 8 to 10 minutes, or until just set. Allow the cookies to rest on the baking sheet for 1 minute before transferring to a wire rack. Cool completely before storing in an airtight container.