Preheat oven to 350°.
Lightly spoon flour into dry measuring cups; level with a knife. Combine flour and next 6 ingredients (through allspice) in a bowl.
Place sugar, egg substitute, oil, buttermilk, and eggs in a large bowl; beat with a mixer at high speed until well blended. Add 2/3 cup water and pumpkin, beating at low speed until blended. Add flour mixture to pumpkin mixture, beating at low speed just until combined. Spoon batter into 2 (9 x 5-inch) loaf pans coated with cooking spray. Sprinkle pecans evenly over batter. Bake at 350° for 1 hour or until a wooden pick inserted in center comes out clean. Cool 10 minutes in pans on a wire rack; remove from pans. Cool completely on wire rack.
This recipe makes two loaves. Freeze the extra bread, tightly wrapped in plastic wrap, for up to one month. Omit the nuts or substitute chopped walnuts, if you prefer. Check the bread after 50 minutes of baking--you may need to cover the loaves with aluminum foil for the last 10 minutes to prevent overbrowning.