Preheat your oven to 350 degrees. Line your cookie sheets with parchment or a silpat mat.
Cream the butter and sugars. Add the eggs and mix just until creamy. Add the vanilla & peppermint extract and stir (or mix in mixer) to combine.
In another bowl, stir the flour, cornstarch, baking soda & salt together. Add to the creamed mixture.
Stir in the white chocolate chips & peppermint crunch chips just until combined
Scoop into balls (my cookie scoop is 1½") and bake for 9-11 minutes. (I cooked mine for 9 because I like a softer cookie).