Preheat oven to 350 degrees. Prepare a deep 9x13 or an 11x18 casserole dish with non-stick cooking spray.

In a large skillet, melt butter over medium-high heat. Add the onion and bell pepper, sauteing for about 5 minutes or until crisp-tender. Stir in the ham and heat through. Transfer to the casserole dish. Top with cheese.

Whisk together the eggs, heavy cream, onion powder, salt and pepper until completely blended. Pour over the cheese, ham, and vegetables.

Bake for 45 to 55 minutes (depending on how deep your casserole is) or until the center is cooked through and the edges are starting to brown.