1 cup chopped pecans
2 cups firmly packed dark brown sugar
1 cup butter, melted
2 large eggs, lightly beaten
2 teaspoons vanilla extract
2 cups all-purpose flour
2 teaspoons baking powder
1/2 teaspoon salt
2 large Granny Smith apples, peeled and diced (about 2 cups)
1/2 cup firmly packed light brown sugar
1/4 cup butter
3 tablespoons milk
1 teaspoon vanilla extract
1 cup powdered sugar
Toffee pieces, optional
Preheat oven to 350º. Bake pecans in a single layer in a shallow pan 8 to 10 minutes or until toasted and fragrant, stirring halfway through.
Stir together brown sugar, melted butter, eggs and vanilla.
In a separate mixing bowl, stir together flour and next 2 ingredients; add to brown sugar mixture, and stir until blended. Stir in apples and pecans. Pour mixture into a greased and floured or foil lined, 8-by-8-inch pan; spread in an even layer.
Bake at 350º for 40 to 50 minutes or until a wooden pick inserted in center comes out clean. Cool completely (about 1 hour).
Bring 1/2 cup brown sugar, 1/4 cup butter, and 3 Tbsp. milk to a boil in a 2-qt. saucepan over medium heat, whisking constantly; boil 1 minute, whisk constantly. Remove from heat; stir in vanilla. Gradually whisk in powdered sugar until smooth; stir gently 3 to 5 minutes or until mixture begins to cool and thickens slightly. Pour immediately over cooled blondie. Top with more toasted pecans and toffee.