Whole Grain Sweet Potato-Banana Muffins

Makes 9 muffins
100 g all-purpose flour (about 3/4 cup)
100 g whole wheat pastry flour (about 3/4 cup)
100 g brown sugar (about 1/2 cup)
10 g baking powder (about 2 teaspoons)
2 g salt (about 1/2 teaspoon)
2 g ground cinnamon (about 1/2 teaspoon)
1/2 large sweet potato, mashed to equal 125 g (about 1/2 cup)
2 medium bananas, mashed to equal 100 g (about 1/2 cup)
1/2 cup milk
1/4 cup oil
1 large egg, lightly beaten
Melted white chocolate (optional)
Preheat oven to 400 degrees.
Whisk together first 6 ingredients (through ground cinnamon) in a large bowl, making a well in center of mixture.
Combine remaining ingredients until blended. Add to dry ingredients, stirring just until moistened.
Using ice scream scoop, portion batter evenly into lined muffin pans.
Bake at 400 degrees for 15 minutes. Remove from pans immediately and let cool on a wire rack. Drizzle with melted white chocolate, if desired.