Preheat oven to 350 F. Line a large baking sheet with a Silpat baking mat or parchment paper and set aside.
In a large bowl, whisk flour, cornstarch, baking soda and sea salt together. Set aside.
In the bowl of a stand mixer, cream together butter and sugars until smooth and creamy, about 3 minutes. Add egg and vanilla extract and beat until combined. Slowly mix in the dry ingredients.
Stir in the chocolate chips and caramel bits. Form cookie dough into tablespoon balls and place on prepared baking sheet, about 2 inches apart. Sprinkle each cookie with sea salt.
Bake cookies for 10 minutes, or until slightly golden brown around the edges. Let the cookies cool on the baking sheet for two minutes. Transfer to a wire cooling rack and cool completely.
Note-I buy the Kraft Caramel Bits at Target. If you can't find Kraft Caramel Bits, you can use caramel squares. Just chop them up into pieces.