AllRecipes and the Food Network provide recipes for plum pudding sauce. AllRecipe's plum pudding makes 4 servings. The Food Network's recipe Nana's traditional Christmas steamed plum pudding with hard sauce makes 8 servings.
For the first recipe, combine 2 tablespoons of margarine, 3/4 cup of white sugar and 1 egg in a small saucepan over medium heat. Pour in 2 cups of milk and cook until the mixture bubbles. Stir in 2 teaspoons of flour and 1 teaspoon of vanilla extract. Mix well and serve.
For the second recipe, mix 1 cup of light molasses, 3/4 cup of melted butter, 1/2 cup of warm milk and 2 beaten eggs. In a large bowl, combine 1 cup of flour, 1 teaspoon baking soda, 1 teaspoon salt, 1 teaspoon cinnamon and 1/2 teaspoon of ground cloves. Add the dry ingredients to the wet ingredients in 3 sections.
Toss 1 pint of candied fruit and 1 cup of raisins with some flour, and then add to the batter. Stir in 1 1/2 ounces of brandy, and then pour the mixture into a greased and sugared steam pudding mold. Place on a rack in a large covered pot with water coming halfway up the mold.
Cover and steam for 2 hours, and then let it cool for 5 minutes before turning out. Dust with powdered sugar and serve with hard sauce. To make hard sauce, combine 1/4 pound of butter, 1 cup of sugar, 1 pinch of salt, 1 teaspoon vanilla extract and 1 ounce of brandy.