In a medium-size mixing bowl, combine the flour, baking powder and salt, and slowly stir them together. Add the brown sugar, cinnamon, and ginger, and stir again to combine.
In a separate bowl, whisk the sweet potatoes, applesauce, milk, egg and vanilla together.
Add the sweet potato mixture to the flour mixture and stir to combine. Take care to scrape the bottom of the bowl so all the flour is incorporated.
Line each muffin cup with a baking cup. Fill each cup 2/3 full with batter.
Bake the muffins for about 18 to 20 minutes or until they spring back when tapped in the center. Let them cool in the pan for about 10 minutes and then remove them from the pan and finish cooling them on a wire rack.