Healthy Harvest Pumpkin Pineapple Loaf   1 1/2 cups granulated sugar 1/4 cup butter 1/2 cup buttermilk 15 ounces solid-pack pumpkin 8 1/4 ounces crushed pineapple, undrained 1 cup egg substitute 1 teaspoon vanilla 3 1/2 cups flour 2 teaspoons baking soda 3 teaspoons pumpkin pie spice 1/2 teaspoon salt 1/4 cup powdered sugar   Preheat the oven to 350 degrees. Spray two 8 ½ by 41/2 inch loaf pans with nonstick cooking spray and set aside.   In a large bowl, beat together sugar and butter until well blended. Add buttermilk, pumpkin, pineapple, egg substitute and vanilla; mix well. Set aside.   In a medium bowl, combine the flour, baking soda, pumpkin-pie spice and salt. Mix well and add to the pumpkin mixture, blending just until all the dry ingredients are moistened.   Divide batter equally into two prepared loaf pans and spread evenly. Bake in the preheated oven for about 50-60 minutes, or until a sharp knife inserted into the center of the loaf comes out clean. Allow to cool for 5 minutes in the pans, then remove from pans and cool completely on a wire rack. Lightly sprinkle with powdered sugar.