Preheat oven to 350 degrees and line a 9x13 baking pan witch parchment paper.
Stir the flour and powdered sugar in a medium mixing bowl to combine. Add the cold and cubed butter and use a pastry blender or two knives to cut the butter into the flour, until it's crumbly. Pour in the water and mix with a spoon until it comes together to form a dough. Press into prepared pan and bake for 15-17 minutes, until golden brown.
2 cups all-purpose flour, 1/2 cup powdered sugar, 4 tablespoons cold water, 1 cup cold unsalted butter
In a medium bowl, whisk together the egg, sweetened condensed milk, pumpkin, pumpkin pie spice and vanilla and mix well.
1 egg, 1-14 ounce can sweetened condensed milk, 1/2 cup pumpkin puree, 1 teaspoon vanilla extract, 1 teaspoon pumpkin pie spice
Fold in the toffee bits and pecans. Pour over the baked shortbread crust.
1- 8 ounce package Heath Bar toffee bits, 1 cup chopped pecans
Bake again for 25-30 minutes or until golden brown. Allow them to cool for 30 minutes in the pan then remove to a wire rack to cool completely before cutting into squares.