Preheat oven to 450℉. Grease with butter or lightly spray an 11x7 inch baking dish with olive oil.
Place your croissant pieces into the baking dish evenly and toast for 5 minutes. It's okay if they're overlapping. Remove from the oven and set aside.
Lower your oven heat to 350℉. Add to your blender the eggs, milk, Boursin cheese, salt, garlic powder, onion powder and blend until smooth. Next, stir in with a fork, 1 cup of your cheese. Then, pour the egg mixture evenly onto your croissants. Top with ham, scallions and the remainig 1/2 cup of cheese. Use your hands to gently press everything down so that the croissants soak up the egg mixture. Cover the dish with foil and bake for 40 minutes. Uncover, increase oven temp to 400℉ and bake for another 10-15 minutes or until golden brown on top.