Preheat oven to 350F
In a large bowl combine butter, sugar and powder sugar and mix until creamed together
Add egg and vanilla and mix again
Add flour and mix until dough forms
Split dough and add ¾ to a lined 9x11 baking dish and press flat
Place remaining ¼ of dough in refrigerator
Bake at 350F for 40 minutes
While baking, make salted caramel by adding granulated sugar to saucepan on medium heat and stirring occasionally until melted
Add room temperature butter and turn heat to low, then stir
Add room temperature heavy cream and stir until combined
Heat for 2 minutes then add flaky salt and remove from heat
Remove bars from oven and top with salted caramel
Add remaining cookie batter in chunks on top
Bake at 350F for 25 minutes
Allow to cool for 15 minutes before serving
