Step 1

Preheat the oven to 400 degrees F. You will need two 7 x 10-inch pans (often called brownie pans). If you do not have those, you may use two 8 x 8-inch baking pans; the bars will be a bit thicker and may require a few extra minutes to bake.

Step 2

Prepare the pie crust if making your own, or unroll the refrigerated crust. Roll to fit the two pans. If using the pre-made crusts, you will overlap one and one half to get the size you need, then trim to fit. Fit them into the pans and crimp the edges.

Step 3

Lightly spray a piece of foil to fit each pan with overlap and lay them, oiled side down, into the pans, pressing against the dough and up the sides. Fill the foil liner with beans, rice, or pie weights and bake for 15 minutes. Remove from the oven and reset the temperature to 350 degrees F. Carefully pull out the foil with the weights and set aside. Return the pans to the oven for an additional 10 minutes until the crust looks dry and is just beginning to brown. Place on a cooling rack. Lightly beat one egg yolk and brush over the surfaces of the crusts. (see note). When the crusts are cooled, spread the chocolate pieces around the bottom of each pan.

Step 4

While the crusts are baking, place the whole pecans on a baking sheet and toast in the oven for 10 minutes. Reserve 20 pecans, which will remain whole for the garnish; chop the rest. Toss the chopped nuts with one tablespoon of flour.

Step 5

With an electric mixer, cream the butter and brown sugar on medium speed for 3 minutes until it is light and fluffy. With the mixer running on medium high add the 5 whole eggs one at a time and then beat in the remaining flour, syrup, molasses, Kahlua, vanilla, and salt. Scrape down the sides and bottom once or twice while mixing. The mixture may look slightly curdled, which is okay. Fold in the chopped nuts by hand.

Step 6

Pour into the two baking pans over the chocolate. Arrange the whole nuts on top so that they will be approximately in the center of the finished bars.

Step 7

Bake for 1 hour until the center of each pan is set and tests done when a toothpick is inserted. Cool on wire racks. Cut into bars to serve.