In the bowl of your stand mixer, cream together the softened ½ cup unsalted butter½ cup brown sugar, and ½ cup granulated white sugar with the paddle attachment on medium speed until smooth.
Lower the mixer speed to low speed and add the ½ cup sourdough discard, 2 egg yolks, and 2 teaspoons vanilla extract. Mix until fully combined, about 30 seconds.
Add the 2 cups all-purpose flour1 tablespoon ground cinnamon, 1 teaspoon ground nutmeg, 1 teaspoon baking soda, and ½ teaspoon kosher salt. Mix on low speed until just combined.
Fold in the 1 2.5 oz bag of apple chips and ¼ cup walnuts or pecans.
Line two cookie sheets with parchment paper. Using a 2-tablespoon cookie scoop, portion the cookie dough and place it on the prepared baking sheets spaced about 2 inches apart
Bake for 14 to 16 minutes or until the edges are lightly browned but the center is still soft.Allow the cookies to cool for at least 5 minutes before transferring them to a wire rack to cool completely.