Make it easy-
start with Pepperidge Farm (or similar) cinnamon-raisin bread, Cubing the bread is very easy...stack 3-4 slices, and cut with electric knife. Use 3/4 cup of sugar in the custard. Light brown sugar, packed, is a very good change. For the custard, I use 2 beaten eggs, and about 2 cups of half-and-half, nicely combined, with the sugar. I use my Braun stick blender for a few seconds. (For the benefit of our friends overseas, half and half is approximately "single cream.") and a spoon of vanilla.
Put the cubed bread into the dish, and pour the custard over evenly. Apply a lot of small dots of butter to the top. Be sure to spray/butter the dish!
Bake in a water bath, 350F, until set and browned on top, about 45 minutes.
Lawrence/Maytagbear