Heat oven to 350 degrees. Grease and flour a 9 x 13 inch cake pan and set aside. In a bowl, combine the boiling water and baking soda; set aside. In a large bowl, sift together flour, ground spices, salt, and baking powder and set aside.
With an electric mixer with paddle attachment, cream the butter until light - about 1 minute. Add brown sugar and beat until fluffy - about 1 minute. Add molasses, water with baking soda mixture and mix until blended. Beat in eggs and beat until blended. Add the flour mixture that has been thoroughly combined.
Pour batter into prepared pan and bake until a toothpick inserted in the center comes out clean - 30 to 35 minutes. Serve warm or at room temperature with either sifted powdered sugar on whipped cream.
Recipe by Baking and Eggs at https://bakingandeggs.com/2016/09/04/gingerbread-cake/