Place the bread crumbs into a small bowl, and mix in the cream. Allow to stand until crumbs absorb the cream, about 10 minutes. While the bread is soaking, melt 1 teaspoon of butter in a skillet over medium heat, and cook and stir the onion until it turns light brown, about 10 minutes. Place onion into a mixing bowl; mix with the ground beef, ground pork, egg, brown sugar, salt, black pepper, nutmeg, allspice, and ginger. Lightly mix in the bread crumbs and cream.