In a large mixing bowl, whisk together the flour and the ¾ cup sugar.
Add the cold, cubed butter to the dry ingredients. Use a pastry blender or your fingertips to cut the butter into the flour mixture until it resembles fine crumbs.
Stir in your chosen extract, a few drops of red food coloring (if you like a pop of color), and the peppermint crunch chips until they are well distributed.
Now, use your hands to gently knead the dough right in the bowl. Continue kneading until all the ingredients come together and form a smooth, cohesive ball of dough.
Shape the dough into a log, about 2 inches in diameter. Wrap it snugly in plastic wrap and place it in the refrigerator for at least 2 hours to firm up. This step is key for perfect slices!
When you're ready to bake, preheat your oven to 325°F (160°C). Line a baking sheet with parchment paper.
Unwrap the chilled dough log. If you want an extra sparkle, roll the log in additional granulated sugar before slicing.
Carefully cut the dough log into ¼-inch thick slices and arrange them about 1 inch apart on your prepared baking sheet.
Bake for 10 to 12 minutes, or just until the edges are lightly set and the cookies look firm. Be careful not to overbake, as shortbread should stay tender!
Let the cookies cool on the baking sheet for several minutes before gently transferring them to a wire rack to cool completely.