Preheat oven to 325°. Line two twelve-cup cupcake pans with paper liners
In a large bowl, sprinkle baking soda over the tomato soup and stir well. Set aside.
In a medium bowl, sift together flour, cinnamon, nutmeg, allspice, salt and baking powder.
Beat butter and sugars together on medium speed until fluffy, three to four minutes. Add eggs, one at a time, and beat until just combined. Scrape down the sides and bottom of the bowl and beat for a few seconds. Turn the mixer to low. Add the flour mixture in three parts, alternating with tomato soup, beginning and ending with flour mixture. Scrape down the bowl again, and mix on low speed for a few more seconds.
Fill the prepared cupcake pan about three-quarters full. Bake the cupcakes 25-28 minutes or until a toothpick inserted in the center of a cupcake comes out clean.
Allow the cupcakes to cool for 30 minutes in the pan, then turn them out onto wire racks to cool completely.