Chop candy bars and set aside.Butter and flour a 13x9x2- inch metal baking pan

Preheat oven to 350°F

Place walnuts in a pan and bake for 8 minutes

Chop nuts

Chop chocolate

Stir butter and chocolate in heavy small saucepan over low heat until melted and smooth

Cool to lukewarm

Whisk flour, salt, and baking soda in small bowl to blend

Using electric mixer, beat sugar, eggs, and vanilla in large bowl until thick and light colored, about 3 minutes

Beat in chocolate mixture, then flour mixture

Fold in walnuts

Transfer to pan

Bake brownies 28 minutes or until set in center

Sprinkle brownies evenly with chopped toffee bars

Cut into squares.