Preheat oven to 325 degrees. Line 2 large cookie sheets with parchment paper.

In a large bowl, whisk together flour, soda, cornstarch, and salt.

In another medium bowl, use a whisk or electric beater to beat together butter and sugars until no lumps remain. Add egg, yolk, and vanilla extract and continue to beat until smooth. Slowly stir in flour mixture until batter comes together. Stir in candy cars, chocolate chunks, pretzels, and peanuts.

Chill dough for at least 2 hours or overnight. If you’re in a hurry, scoop 2 heaping Tablespoons (or 2 ounces) of dough in round balls onto cookie sheets and freeze for 15 minutes before baking.

Bake for 11-13 minutes, rotating the pans halfway through. The cookies will look soft and underdone. That’s okay. Allow them to set up on the baking sheet for 3-4 minutes then remove to a wire rack to cool completely.

Cookies keep in an airtight container for up to a week.