Caramel Shortbread (gluten free)

My husband loves shortbread (maybe it's a British thing?) and caramel.  So when I saw recipes floating around for a mixture of the two I knew I had to try it.

METHOD
In food processor, combine until crumbly:
1 C butter (that's 2 sticks)
1/4 C sugar
2 C gluten free flour (I use a mix of brown rice flour with potato starch and tapioca starch)
1/4 tsp salt

Press into a 9x9" pan.  Bake at 350 F until starting to turn golden brown, 25-30 minutes

Once the shortbread is done, in a small saucepan on the stove, melt 1/2 C butter (that's just 1 stick).  Once melted add the content of 1 can of sweetened condensed milk and bring to a boil.

Boil, while stirring and scraping the bottom of the pan, for 5 minutes. It will thicken and turn a darker color.

Turn off heat. Pour in 1 tsp vanilla extract, stir. Pour over the shortbread in the pan. Let cool. Once the pan has cooled off, put in the fridge.

When ready to serve, cut into slices.

To freeze, cut into squares and separate on a cookie sheet. Freeze them while separated, then transfer to a bag.