In small bowl, combine flour and salt. In large microwave safe bowl, melt the butter and chocolate. Stir in sugar. Add eggs and vanilla extract; mix well. Stir in flour mixture; mix until just combined. Stir in 1/4 cup pecans, chocolate chips and toffee chips. Spread batter evenly into prepared pan. Sprinkle remaining 1/4 cup pecans evenly over top.