Use about a 9x9 inch baking dish 3 or more inches deep.
Spread bread slices with real butter and cube into 9 squares. Place a tight even layer in the bottom and sprinkle raisins all over it and a little cinnamon over that. Do three layers like this, and top off with raisins and cinnamon.
Beat 6 eggs, pinch of salt, 1 teaspoon vanilla and a rounding 1/2 cup of sugar. Add 2 cups of milk and beat well. Pour slow over the bread and let it soak for 45 minutes. Keep adding mixture, when you put it in the oven it has to be covered. If you don't have enough liquid, add milk. Bake at 350 degrees for 1/2 to 3/4 hour, until golden brown.