Step 1Heat the oven to 350 degrees. Butter a 9-inch cake pan and dust with flour.
Step 2Sift together the flour, salt and baking soda.
Step 3Using an electric mixer, beat the egg and one-half cup of the sugar together. Mix in the pumpkin, oil, molasses and spices until combined and smooth. Mix in the boiling water.
Step 4Mix in the dry ingredients.
Step 5Pour the batter into the pan and bake for 35 to 40 minutes or until a skewer inserted in the center comes out clean. Cool in the pan on a rack for 10 minutes. Remove from the pan.
Step 6Mix the cream, rum and remaining 1 tablespoon sugar together and whip to soft peaks. Serve on the warm gingerbread.