Heat oven to 375°F. Line 9x13 inch baking pan with foil. Beat together butter, shortening and sugars till combined. Add baking soda. Beat in eggs and vanilla till combined. Beat in as much flour as possible with mixer and stir in remaining. Stir in chips and nuts. Press evenly into prepared pan. Bake 22-25 minutes till golden brown and center is set. Cool in pan on rack 1 hour. Heat oven to 325°F. Remove from pan using foil and place on cutting board, leaving foil on cookies. Cut in half crosswise. Cut halves crosswise into 1/2 inch slices. Place cut sides down, 1 inch apart, on ungreased baking sheet. Bake 6-8 minutes till edges are crispy. Carefully transfer to rack to cool completely.
Make Ahead Tips
Bake and cool completely. Freeze up to 3 months. Thaw 15 minutes before serving.

Each serving: 333 calories, 4 g protein, 39 g carbohydrates, 20 g fat (8 g saturated), 2 g fiber, 37 mg cholesterol, 98 mg sodium