In a medium bowl, stir together the all-purpose flour and salt. Set aside.
In the bowl of a stand mixer fitted with a paddle attachment, on medium speed, beat together the unsalted butter and granulated sugar for 2 to 3 minutes or until light and fluffy. You will need to stop the mixer halfway through and scrape down the bowl and paddle attachment to ensure that you get a nice smooth mixture.
Add the peppermint extract and liquid red food coloring to the beaten butter. Beat for an additional 30 seconds to fully incorporate the food color with the butter. You want your beaten butter to be uniform in color.
Next, add half of the dry ingredients to the bowl of the stand mixer and mix on medium-low just until the flour has been incorporated into the butter.
Scrape down the sides of the bowl and the paddle attachment, add the remaining half of the dry ingredients, and mix again just until the flour has been incorporated.
Lastly, add the finely chopped Andes Peppermint crunch candies and mix on medium speed for 30 to 45 seconds or just until the candies are fully incorporated, and the dough comes together in a rough ball and pulls away from the sides of the bowl.
Form your cookie dough into a log that measures approximately 12 inches long by 2 inches in diameter.
Wrap your cookie dough log tightly in plastic wrap and refrigerate it for at least 6 hours or up to overnight.
Preheat the oven to 350°F. Line a large baking sheet with parchment paper.
Slice your chilled dough into ½-inch thick slices. Place your sliced cookie dough 2 inches apart on the prepared baking sheet.
Bake for 12 minutes or just until the center is set and the edges are just barely starting to get a light golden brown. You do not want to overbake your cookies.
Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a cooling rack to cool completely.