Preheat oven to 350 degrees Fahrenheit.
Grease and line a 9"x13" baking dish with parchment paper. Set aside.
Cream together the butter and shortening.
Add the egg and egg yolk, beating until well incorporated.
Beat in the sugar and cinnamon.
Add the flour, salt, and baking powder, mixing until just incorporated.
With a silicone spatula, spread the mixture into the bottom of the prepared pan. It will be sticky. Just be patient.
Brush all of the egg white over the top of the mixture.
In a medium bowl, mix together the granulated sugar, cinnamon, walnuts, and semi-sweet chocolate chips for the topping. Sprinkle evenly over the bars.
Bake for 25-30 minutes, or until edges are lightly browned. Be careful not to overbake!
Cool completely before removing from pan and cutting. This is very important! They will fall apart if you are not patient.