1
: Combine 1 cup (250 mL) flour and sugar, cut in butter until crumbly. Press firmly on bottom of parchment paper-lined 13x9" (3.5 L) baking pan. Bake in preheated 350ºF (180ºF) oven, 15 minutes.
2
: Beat sweetened condensed milk, cocoa, egg, remaining 1/4 cup (50 mL) flour, vanilla and baking powder. Stir in chocolate chunks and nuts. Spread over baked crust.
3
: Bake 20 minutes or until set. Cool. Cut into bars. (Store tightly covered at room temperature.)