Ginger-Spiced Pumpkin Muffins

1 1/2 cups whole wheat flour
1/2 cup packed brown sugar
1 egg
1 cup milk
1 cup canned pumpkin (or more if you like)
2 tsp. baking powder
1 tsp. ground cinnamon
1 tsp. ground ginger
1/2 tsp. salt
1/4 cup vegetable oil
1/2 tsp. orange zest (optional)

Mix and bake at 375 degrees for 15-17 minutes