Preheat oven to 325 degrees F.
Line a 9×13 pan with parchment paper or aluminum foil. Lightly spray with cooking spray.
In a large mixing bowl cream together butter, sugar, and powdered sugar.
Add sour cream, IOWISH SALTED CARAMEL LIQUEUR and mix until combined. Mix in the flour and combine until it forms a soft dough.
Press half of the dough in the bottom of a 9×13 dish and place the other half of the dough into the refrigerator. (Do your best dividing it in half- I think mine ends up being 2/3 in the pan and the remaining 1/3 in the fridge and it still turns out well!)
Bake crust in preheated oven for 15 minutes.
While the crust is baking, melt the caramels, heavy cream and 1/2 tsp vanilla in the microwave for 1 minute. Stir together until smooth, adding more time in 30-45 second increments as needed. Try and get it as smooth as you can, depending on the type of caramel, it might not be perfectly smooth and that’s okay!
Pour caramel evenly over the hot crust. Lightly sprinkle about 1 tsp coarse sea salt over the caramel.
Take the remaining dough out of the refrigerator and crumble over the top of the caramel. Return the pan to the oven and bake for 25-30 minutes until filling is bubbly and the top is firm.
Add remaining 1 tsp salt after caramel bars are cooled, but before cutting.
Let them cool completely before cutting into small squares.