Separate Spices Option: Substitute 1 teaspoon ground cinnamon + ½ teaspoon ground ginger + ¼ teaspoon allspice + ¼ teaspoon ground nutmeg for the pumpkin pie spice.
Nut Option: Fold ½ chopped walnuts into the batter before scraping it into your prepared pan. You can also optionally add ¼ cup chopped nuts to the streusel.
Glaze Option: For even more indulgence, whisk together 1 cup sifted powdered sugar, 1½ tablespoons water, and ¼ teaspoon vanilla extract in a medium bowl. If it's too thick for drizzling, gradually whisk in more water, ½ teaspoon at a time, until it reaches a thin, pourable (but not drippy) consistency. Drizzle it over the completely cooled pumpkin streusel bread.
Nutrition Note: One thick slice also provides about 100% of the RDA for vitamin A. It's also a good source (10% or more of the RDA) of folic acid, vitamin K, vitamin E, and iron.