Preheat oven to 350 degrees. Grease and flour a Bundt pan. Cream sugar and butter until light. Add eggs, one at a time, beating after each addition. Add buttermilk to egg mixture. Mix well. Sift flour, soda, cinnamon, and nutmeg in a separate bowl. Mix dry ingredients into egg mixture. Blend in jam. Spoon into prepared pan. Bake 30 to 40 minutes, or until firm. Cool slightly. Remove from Bundt pan. Serve warm with vanilla sauce.