We found this recipe here, but made just a couple substitutions and upped the amount of spices.
Muffins Ingredients:
1 cup whole wheat pastry flour
1/4 cup whole wheat flour
1/4 cup cornmeal
1/2 cup oats
1/4 cup sugar OR sucanat
2 teaspoons baking soda
1 teaspoon cinnamon
1 teaspoon ground ginger
1/4 teaspoon salt
1/4 teaspoon allspice
1 cup buttermilk (or make your own with 1 cup whole milk with 1 tablespoon vinegar)
1/2 cup mashed, roasted butternut squash (or pumpkin puree, if you prefer)
2 large eggs
1/4 cup unsalted butter, melted and cooled
1/4 cup yogurt
Topping Ingredients:
1/2 cup chopped pecans
1/3 cup oats
1/4 cup brown sugar OR sucanat
1/4 tsp cinnamon
1 tablespoon whole wheat flour
1/4 cup melted butter