Spray a 9x13 baking pan with non-stick spray. Cube the loaf of bread and mix in the raisins. Put in baking pan.
In a blender, mix the eggs, milk, cinnamon, nutmeg, vanilla, rum flavoring, and salt. Blend till foamy.
Slowly pour the egg mixture over the bread, soaking each piece. At this point you can cover it and refrigerate it over night, or continue.
In a small mixing bowl, melt the margerine and then stir in the corn syrup, brown sugar, and optional nuts. Drizzle it over the bread mixture.
Bake at 350 degrees for 45 minutes. Cut into servings of 8 to 10 pieces. Serve hot with margerine and warm syrup.
This makes a "rum raisin" flavor. For other flavors, try using orange zest and cranberry raisins, or lemon zest and blueberries instead of the raisins and rum.