1) Preheat oven to 350°F. Spritz a 9" round cake pan with cooking spray. Line with a parchment circle and spritz with spray again. Cream butter and sugar in large bowl. Add egg and mix well.
2) Combine baking soda with undiluted soup in can. Let foam for 1 minute. Pour soup mixture into butter/sugar/egg and blend well. Mixture will look slightly curdled. This is normal.
3) In a small bowl combine flour, baking powder and spices. Whisk well and add to tomato soup mixture. Beat together for 1 minute on medium speed. Pour into prepared pan and bake for 30-35 minutes. Cool on wire rack and ice as desired.