To make crust: Beat flour, butter and brown sugar in a small mixing bowl until crumbly. Press into a greased 13 x 9-inch baking pan. Bake at 350 degrees F for 12 to 15 minutes or until lightly browned.
To make filling: Beat eggs, corn syrup, sugar, butter and vanilla in a medium bowl with a wire whisk. Stir in chunks and nuts. Pour evenly over baked crust. Bake for 25 to 30 minutes or until set. Cool in pan on a wire rack.