Lightly grease the bottom and sides of a 9×13'' baking dish. Cut bread into 1 inch chunks and place in dish.

Crack the eggs into a large mixing bowl and whisk to combine. Add the cream and milk, brown sugar, cinnamon, salt and vanilla and mix well. Pour evenly over the bread cubes.

Gently toss the bread around a little to make sure the top and bottom pieces all get dipped in the egg mixture. Spread out evenly, cover dish, and refrigerate overnight.

For the Topping: Place brown sugar, white sugar, cinnamon and nutmeg in a bowl and stir to combine. Cut cold butter into small chunks and add to the bowl. Use a pastry blender or your hands to combine the mixture until crumbly. Cover and refrigerate until morning.

Preheat oven to 350 degrees F. Uncover french toast pan and sprinkle the topping evenly over top. Bake for 45-50 minutes or until top is golden and casserole is set.

Allow french toast to cool for at least 10 minutes before serving. Top with homemade syrup, berries, whipped cream or any other toppings you'd like.