I know this recipe looks very involved, but Melanie says it is so easy that even Talmadge Skillman has made it on his own, with no help from Momma, and it turned out delicious. You can also sprinkle some sea salt on top, if you wish.
1 cup butter, softened
1/3 cup sugar
1/3 cup light brown sugar
1 large egg yolk
3/4 tsp. vanilla extract
2 1/4 cups all-purpose flour
Preheat oven to 350 degrees and line a 13×9 dish with parchment paper. In a medium bowl, beat butter with an electric mixer until well creamed. Add sugars and beat until light and fluffy. Add egg yolk and vanilla and stir well. Add flour, gradually, pausing to scrape down sides of bowl. Drop dough into prepared pan and evenly press it out to cover the bottom. Bake for 20 to 25 minutes until edges are light golden brown. Allow to cool.
2 (14-oz) cans sweetened condensed
14 Tbsp. butter cut into Tbsp.-sized
1 cup (packed) light brown sugar
1/3 cup light corn syrup
1 tsp. vanilla extract
1/4 tsp. salt
Combine condensed milk, butter, brown sugar, and corn syrup in a medium-sized saucepan over medium heat. Stir frequently until butter is melted and ingredients are well combined. Stir constantly until mixture begins to boil (this could take several minutes). Once it comes to a boil, reduce heat to simmer. Continue to stir constantly for 10 to 15 minutes until mixture turns a rich caramel color and has thickened (should begin pulling away from the sides as you stir). Remove from heat and immediately stir in the vanilla and salt. Pour evenly over the prepared shortbread. Allow to cool in the refrigerator for one hour.
2 cups semisweet chocolate chips
1/2 cup heavy cream
1/2 tsp. vanilla extract
Combine chocolate chips and heavy cream in a small saucepan over medium heat. Stir frequently until chocolate is melted. Remove from heat and stir in vanilla. Allow the mixture to cool 5 minutes, then spread evenly over the caramel layer. Refrigerate 30 minutes before serving so chocolate can harden.