Add the croissants. In an even layer in the pan. Having all the layers of torn croissant pieces means there will be so many places for the custard base to hang out.
Pour the custard over the croissants. Press down gently. To ensure the custard is soaking into all of the croissants. Give it a toss to coat if you're feeling like it.
Bake the casserole. Either right away or let it hang out in the fridge overnight and then bake.
Serve! With whipped cream, powdered sugar, and fresh berries. To die for!