In a bowl, whisk together all the dry ingredients (the first 6 ingredients listed) and set aside.
In another bowl, cream the butter with the sugars until light and fluffy.
Add in the egg and vanilla and continue to beat until well- incorporated.
Stir in the dry ingredients until everything is blended. It should be quite thick.
Fold in the apple chunks and 3/4 of the white chocolate bits.
Cover the bowl with cling wrap and pop in the refrigerator for 1 hour or overnight.
Preheat the oven to 350 F or 180 C.
Scoop the dough into 1 - 1 ½ sized balls (the longer you chill the easier the dough is to work with) and roll in the cinnamon sugar until coated. Freeze for around 15-20 minutes before baking, or until firm.
To bake, place the balls about 2 inches apart on a cookie sheet lined with parchment paper.
Bake for 8-9 minutes or until the edges are golden brown and the center is slightly puffy.
Immediately when the cookies come out of the oven, place 2-3 chocolate chips (from the remaining ¼ cup) into each cookie. The cookies should be soft enough and warm so that the chips begin to melt and stick.
Cool completely before serving.