Mix your liquids. In a bowl mix together the eggs, milk, heavy cream, salt, and vanilla extract. Whisk together until fully combined. Set aside.
Soak Bread. Place the bread cubes in a greased 9×13 inch casserole dish and pour the egg mixture over the bread making sure to moisten all of it. Cover with plastic wrap and place in refrigerator for at least 3 hours, preferably overnight.
Preheat & Bake. Remove the casserole from the refrigerator, take off the plastic wrap, and let it stand while you preheat oven to 375 degrees F. Once preheated place the casserole in the oven and bake for 45 – 55 minutes. When the casserole has finished baking remove from oven and let cool for 10-15 minutes.
DOES FRENCH TOAST BAKE HAVE TO SIT OVERNIGHT? No. While you can totally make this french toast bake and let it sit overnight to save yourself some time in the morning you certainly don’t have to. If you don’t have all night, or even 3 hours, to let this casserole sit in the refrigerator just combine your bread and the egg and milk mixture according to the recipe and then gently press down on the bread to help it absorb more of the liquid. Don’t press it flat or anything, you don’t want to mash the bread together, but press down lightly and then let it spring back a little. Do this a couple of times to help the bread suck up the liquid like a sponge. Let it sit for at least 30 minutes and then bake. You’ll have a delicious french toast and no one will be the wiser.