Preheat the oven to 350°F. Line two baking sheets with parchment paper and set aside.
In a large bowl, cream together the butter and sugars until light and fluffy. Add in the egg and vanilla, and mix until fully incorporated.
In a separate bowl, mix together the flour, cornstarch, baking soda and salt. Mix the dry ingredients into the wet ingredients until fully combined. Fold in the salted caramel and white chocolate chips.
With a cookie scoop, scoop the cookie dough onto the prepared baking sheets, and bake in the preheated oven for 8-10 minutes, or until lightly browned. Allow to cool completely on baking sheet.