Heat oven to 325 degrees (I've cooked these at 350 as well and it works, as well. Just watch your baking time). Adjust oven racks to upper- and lower-middle positions. Mix flour, salt, and baking soda together in medium bowl; set aside.
Mix butter and sugars until thoroughly blended. Mix in egg, yolk, vanilla and peppermint extract. Add dry ingredients; mix until just combined. Stir in chocolate chips and candy cane.
Use a cookie scoop of your choice (I make these large, about 2 tablespoons). Take the rounded scoops and lightly dip the tops in additional crushed candy cane. Don't roll completely, just a little sprinkling is great! Chill dough for 15-30 minutes to help cookies retain their shape. Bake until outer edges start to harden yet centers are still soft and puffy, 10-13 minutes depending on the size.
TIP: When the cookies come out of the oven, if they aren't completely round, you can immediately take a spatula or spoon and gently push the edges of the cookies inward toward the center to shape. Cool cookies on cookie sheets. Serve or store in airtight container.