Make breakfast ahead of time with this overnight apple cinnamon french toast. Prep it the night before so all you need to do in the morning is pop it into the oven!
Lightly coat a 9x13-inch baking dish with butter or nonstick spray and set aside.
In a large bowl, whisk together eggs, milk, butter, brown sugar, cinnamon, vanilla, and salt until frothy. Dip each slice of bread into the liquid to coat completely, then arrange bread in the prepared pan, overlapping slices. You may need to cut a few slices to fit and fill in any gaps. Pour any remaining custard liquid over the top.
In another bowl, combine apples, lemon juice, brown sugar, cinnamon, and nutmeg. Stir well to dissolve sugar. Tuck apple slices in between bread, then pour any accumulated juices over the top.
Cover tightly with plastic wrap and place in the refrigerator overnight.
When ready to bake, remove from refrigerator and preheat oven to 350°F. Remove plastic wrap and bake for 40 minutes. Serve with powdered sugar and maple syrup.
Notes
Make sure to remove pan from the refrigerator before turning on the oven to help it warm up before baking.
You can sauté the apples with 2 tablespoons butter and the rest of its ingredients until just softened before adding to the casserole dish, if you like.