To crush your candy pieces, place them in a baggie and gently pound with a rolling pin being careful to leave med sized pieces and not a fine powder. You want them about the same size as your white chocolate chips. The larger the pieces the less spread. Fine pieces will cause the cookie to spread too much) Set some aside to press into the top of each cookie once they're rolled and ready to bake. 

Whisk the flour, sugar, brown sugar, baking soda, salt, and cornstarch together in a medium bowl. In a large bowl add softened butter, egg, vanilla extract, and peppermint extract. Using a hand-held mixer beat until completely smooth and creamy.

Slowly add the dry ingredients into the wet ingredients and mix on low until combined. The cookie dough will be thick. Once combined, add the white chocolate chips and most of the crushed candy cane. Hand stir until combined. Cover the dough tightly with plastic wrap and chill for at least 2 hours and up to 3 days. Overnight is best. It's important not to skip this step. Warm cookie dough yields cookies that spread too much.

Preheat oven to 350°. Remove cookie dough from the refrigerator. Line 2 large baking sheets with parchment paper or silicone baking mats. (I LOVE the Silpats from Williams Sonoma) Set aside.

Roll dough into individual balls, about 1.5 Tablespoons of dough each, and place them onto your cookie sheet leaving space for spread. Press a few extra pieces of peppermint candy onto the tops of each ball.

Bake for 14 minutes, or until lightly golden brown around the edges. Allow them to cool for about 5 minutes on the cookie sheet, then transfer to cooling rack to cool completely.