To make this Chocolate Croissant Breakfast Bake gluten free, replace the croissants with certified gluten-free croissants or a gluten-free buttery bread-style pastry. Verify that the semi-sweet chocolate chips, vanilla extract, whole milk, heavy cream, sugar, salt, butter, and all packaged ingredients are labeled gluten free or free from gluten-containing additives. Use clean mixing bowls, utensils, measuring cups, parchment paper if used, and a clean baking dish to prevent cross-contact with gluten-containing ingredients.