Grease a 3 quart casserole dish, such as a 9"×13" casserole dish.
Place half of the brioche slices into the dish without overlapping them. It's OK to squeeze them a little to make them fit.
Spread the cream cheese evenly over the brioche.
Spread the jam evenly over the cream cheese.
Evenly distribute the raspberries on top of the jam.
Top with the rest of the bread, creating a bunch of sandwiches.
In a large bowl, whisk together the remaining ingredients and pour evenly over the entire dish.
Cover the casserole dish and refrigerate overnight.
When ready to bake, preheat the oven to 350 F.
Keep the casserole dish covered and bake for 90 minutes or until no liquid remains.
Serve immediately.
Notes
Make sure the cream cheese and jam are spread evenly over the bottom layer of bread. If necessary, warm them for a few seconds in the microwave to help make them more spreadable.
Make more stuffed French toast than you think you will need. Because you are essentially making sandwiches, people are inclined to take a whole sandwich as their portion - which is larger than they would have taken with regular French toast.