Prepare a 12-cup muffin tin by lining 10 of the cups with paper cup liners or by spraying with cooking spray. Set aside.
Preheat oven to 400 degrees F.
In a medium bowl, whisk together brown sugar, molasses, milk, oil, applesauce, and egg until well blended.
In a large bowl, whisk together remaining ingredients.
Add wet ingredients to dry ingredients, stirring just until combined. Batter will still be slightly lumpy, which is fine – do not overmix.
Scoop batter into prepared muffin cups. I like to use an ice cream scoop for this part so that all of my muffins are the same size.
Bake for about 15 minutes, or until a toothpick inserted in the center comes out clean. Remove from pan and cool on a wire rack.