In a medium bowl, beat egg. Stir in sourdough starter, pumpkin, raisins, milk, oil and nuts, if desired. Stir into spice mixture until dry ingredients are just moistened. Turn into prepared pan or pans. Bake in preheated oven 35 to 40 minutes for small loaves or 50 to 55 minutes for other loaves.
Bread is done when a wooden pick inserted in center comes out clean.
Turn out of pan or pans. Cool top side up on a rack. Prepare Golden glaze. Spread on cooled pumpkin loaf or loaves. Combine powdered sugar, half and half and food coloring.