Add the butter, both of the sugars, egg, vanilla, and peppermint extract to the bowl of a stand mixer.
Mix on high until it turns into a smooth and well-combined mixture.
Sift the flour into another bowl.
Add the salt and baking powder to the flour and whisk it together.
Add half of the dry mixture to the bowl with the butter and sugar mixture and mix.
Add the remainder of the dry mixture to the wet mixture and mix it all together.
Add the white chocolate chips and fold them into the cookie dough.
Refrigerate the dough for one hour so it doesn't spread too much when baking.
Preheat the oven to 375 degrees and line your baking sheet with the parchment paper.
Use a medium cookie scoop to add 1-1/2-inch cookie dough balls, taking care not to overcrowd the cookie sheet.
Bake the cookies for about seven minutes or until the edges are golden.
As soon as you remove the cookies from the oven, sprinkle the candy canes on top.