In large bowl, whisk together flour, cornstarch, salt, baking powder, and baking soda until well combined; set aside.
In a separate large bowl, beat together brown sugar, granulated sugar, and butter with an electric mixer on medium speed until well combined. Add egg, egg yolks, and vanilla, and beat until well combined.
Beat flour mixture into wet mixture until combined. Stir in melted chocolate, then stir in chocolate chips, pecans, and caramel bits. Drop dough (or use ice cream scoop) in 2 tablespoon balls on baking sheets that have been lined with silpats (or parchment paper or wax paper).
Cover cookie dough balls with plastic wrap and refrigerate dough for at least a few hours but better overnight or up to a few days. Or do not cover dough and place dough balls in freezer for a few hours until dough is hard then place balls in resealable bags and back in freezer.
Preheat oven to 325 degrees F. Place cookie dough balls in batches on baking sheets that have been lined with parchment paper (or silpats). Bake refrigerated dough for about 15-18 minutes or until golden brown and look slightly undercooked (about 17-22 minutes for frozen dough), turning pans halfway through baking. Cool cookies on wire racks.
SNAPPY TIPS: I strongly suggest refrigerating the dough for best results and not baking right away. You can make a big batch of the basic dough then use it for other upcoming recipes.SNAPPY SUBSTITUTIONS: You can substitute any type of chips for the chocolate chips or any kind of nuts for the pecans. I do not suggest substituting margarine for butter or whole eggs for the egg yolks. Results will vary a lot the more you substitute.
Keywords: Christmas chocolate cookie, homemade drop cookie