Preheat the oven to 400°F. Line 16 muffin-pan cups with paper liners or spray with nonstick cooking spray. In a large bowl, stir together the flour, baking powder, cinnamon, and nutmeg. In a medium bowl, beat the egg substitute with a whisk. Add the Splenda, pumpkin, milk, and applesauce; stir until well blended. Stir the raisins or chopped nuts into the flour mixture until just blended. Fill the muffin-pan cups 2/3 full. Bake 20 to 25 minutes, or until a wooden toothpick inserted in the center comes out clean. Remove the muffins from the pans. Serve warm or at room temperature.