Place a cupcake liner into each of the 12 cupcake or muffins wells; set aside.
In a medium bowl, whisk flour, ginger, baking soda, cinnamon, and all-spice together; set aside.
In a large bowl using an electric mixer, beat butter and brown sugar together until light and fluffy. Mix in the egg and molasses until just combined.
Fold in the flour mixture alternating with the hot water in 2 parts. Note: Batter will be thick.
Using an ice cream scoop for even measure, scoop 1 mound of batter into each of the lined cupcake wells.
Bake for 15 to 20 minutes or until a toothpick inserted in center comes out clean. Allow cupcakes to cool over a wire rack to room temperature before frosting.
Meanwhile, in a large bowl using an electric mixer on medium speed, beat all frosting ingredients—butter, Philadelphia Cream Cheese, brown sugar, cinnamon, vanilla, and confectioners’ sugar—until smooth.
In a new piping bag, fill frosting about half full. Twist the open end closed to prevent backflow, and cut the tip of the plastic to create a hole, about ½ inch in diameter.
Using your dominant hand with the cupcake on the counter, angle the piping bag vertically. Gently squeeze the back of the bag to push frosting onto the cupcake. Continue pushing frosting through until a large “cloud” begins to form. Before releasing the bag away from the frosting, repeat again, this time pushing less frosting through. Lift and release to create a peak.
Sprinkle cinnamon if desired. ENJOY!