Set the oven temperature to 400°F. Line a muffin pan with paper liners or lightly spray the pan with cooking spray.

In a large bowl, combine the flour, brown sugar, cinnamon, ground ginger, baking powder, baking soda, salt, and allspice. Set aside.

In a separate medium bowl, combine the melted butter, molasses, vegetable oil, milk, egg, and vanilla.

Add the wet ingredients to the dry ingredients and stir until well incorporated. Do not over-mix. Fill the cupcake liners 3/4 full with the batter.

Bake the muffins 10 minutes. After 10 minutes, reduce the heat to 350°F and bake for an additional 8 to 10 minutes or until a toothpick inserted into the center of the muffin comes out clean.

Remove the muffins from the oven and let them cool on a cooling rack. Sprinkle with confectioners sugar and serve warm or at room temperature.