I had this recipe for years and I can't really tell where did it come from. Well, a few days ago I found it again in my wide recipe collection and decided to make them. I was pleased with the results! These bars are really delicious. The bottom layer is a chewy brownie and the top layer reminds me of a cookie. The sides are crispy and, of course, the interior is chewy!
P.s. Finally the good weather is here and I'm posting some of my photos!
Position rack in lower third of oven. Preheat to 350° (180C). Line bottom and sides of an 8″ (20cm) baking pan with foil, leaving an overhang on two opposite sides.
Combine butter, sugar, cocoa and salt in a medium heatproof bowl and set in a wide skillet of simmering water. Stir from time to time until mixture is melted, smooth and fairly hot. Remove from skillet and set aside briefly until mixture cools a bit.
Stir in vanilla and egg with a wooden spoon. When batter is thick and shiny, add flour and stir until mixed in. Then beat vigorously for 40 strokes. Spread evenly in lined pan.
Mix flour and baking powder together and set aside.
Combine melted butter, sugar and salt in a medium bowl. Stir in egg yolk and vanilla. Then add flour mixture, followed by nuts. Drop spoonfuls over the top of brownie batter.
Bake until edges of topping are well-browned, about 20-25 minutes (I baked them for 25 minutes but next time I'll try to bake them for 20 minutes to make them even chewier). Cool completely in pan on a cooling rack.
Lift up ends of foil liner. Cut now, or after refrigerating.