Preheat oven to 350 degrees and spray your muffin pan with cooking spray.
Cream the butter, oil, sugar and brown sugar in a stand mixer until light and fluffy (about 2-3 minutes). Scrape the sides of the bowl to make sure all ingredients are blended.
Add in egg and vanilla and beat until combined.
Add in flour, baking powder, corn starch and salt. Mix until all combined. Scoop about 1 TBSP of dough into the muffin cups, making sure they cover the bottom and sides. Bake them for about 10 minutes or until golden and puffy.
Once you remove cookies from the oven, immediately make an indentation in the center of each cookie with the bottom of a shot glass or just a small water bottle cap. Let the cookies cool in the muffin pan.
Place the caramels and heavy cream in a microwave-safe bowl and melt in microwave 30 seconds at a time stirring in between.
Stir. Spoon the caramel filling into the center of each cookie cup. Refrigerate the cookie cups for about 15 minutes or until the caramel is set.
The next step is to make the chocolate topping. You can either melt chocolate chips with some oil in a microwave-safe bowl or use a double boiler over simmering water. Stir until smooth and glossy.
Remove the cookie cups from the refrigerator and tip each cookie cup top in the chocolate until it covers half of the cookie cup. Refrigerate the cookie cups for another 15 minutes or until the chocolate is set. Enjoy.