- In a large mixing bowl add half and half, eggs, maple syrup, and vanilla. Chop your croissants and arrange in a 13 x 9 baking dish. Pour over the croissants and top with pecan pieces.
- To make the crumble: Add butter, brown sugar, salt, and oats in a bowl. With your fingers or pastry cutter rub the mixture together until it resembles a crumble. Sprinkle over the bake. For best results cover and refrigerate overnight in order for the croissants to soak up some of the liquid.
- Bake at 350 degrees F. Loosely cover with tin foil for 20 minutes. Remove foil and continue to bake for an additional 30 minutes