Preheat oven to 350 degrees.
In a large bowl of a stand mixer fitted with the paddle attachment, combine the butter and brown sugar until light and fluffy. Beat in the eggs, one at a time, mixing until the yolk disappears. Add the water and molasses. The mixture will appear curdled, this is normal. Mix on low 1-2 minutes.
In a medium mixing bowl whisk together the flour, cinnamon, baking powder, baking soda, salt, ginger, nutmeg, and allspice.
With the mixer set on low speed, add the flour mixture to the creamed butter and molasses a little at a time until combined. Once incorporated, beat on medium for 2 minutes.
Fill paper-lined muffins cups two-thirds full and bake for 20-23 minutes for until a toothpick inserted near the center comes out clean. Cool for 10 minutes before removing from the pan, then cool on a wire rack. Frost as desired.