Absolutely; in fact I recommend it, especially if serving for brunch. Just pop the chilled french toast pots in the oven to bake and you can focus on entertaining. The night before make and assemble as in the recipe, then cover each pot in clingfilm or kitchen foil and chill overnight in the fridge until you're ready to bake. Before baking let the french toast pots come up to room temperature for 15 minutes. This takes the chill off and allows for more even baking.