CHOCOLATE CARAMEL PECAN BARS ~ 3 c. pecans, roughly chopped - CRUST - 1 c. flour...1 c. white whole wheat flour...2/3 c. powdered sugar...3/4 c. cold butter, cut in small bits...FILLING - 1 (14-oz.) can dulce de leche (here's a recipe from The Fountain Avenue Kitchen to make it in the slow cooker)...2 t. vanilla extract...1/4 - 1/2 t. salt...2 T. butter, melted...Milk or fat-free half & half, as needed to thin the caramel...1 c. semi-sweet or dark chocolate chips