Chocolate-Caramel Shortbread

I first saw these on Chocolate and Zucchini; someone had bought her some in a store. Then I saw that Harry and David was selling them for the holidays, as I think a Scottish treat. So when the recipe popped up as one of Allrecipe's top Chirstmas cookies and they looked really easy to do, I tried them. And my family hoarded them.

You make the shortbread layer first: Cut 2/3 cup butter up into small cubes, then put it in a bowl and let it come to room temperature. Add 1/4 cup sugar and 1 1/4 cup flour and mix, then press into the bottom of a 9-inch-square pan (I coated mine with cooking spray) and bake at 350 degrees for 20 minutes.

While that bakes, make the caramel layer: Combine 1/2 cup each brown sugar, sweetened condensed milk and butter with 2 tablespoons light corn syrup. Bring to a boil and boil 5 minutes (I was nervous at this point and kept stirring it, and would stir up really brown parts, but that didn't hurt anything - I think the stirring off the heat gets everything even and fully incorporated), then remove from heat and stir vigorously for 3 minutes. Pour over baked shortbread and let it get firm.

The last layer is just chocolate chips: melt 1 1/2 cup chocolate chips (I used bittersweet) and spread over the caramel. Refrigerate to set then cut into teeny-tiny squares.