Preheat your oven to 350°F (175°C).

In a large mixing bowl, combine all your chopped vegetables—bell peppers, zucchini, onion, and spinach. Add in your seasonings, including garlic powder and onion powder.

In a separate bowl, mix the cream cheese and eggs until smooth and well-combined.

Pour your creamy mixture over the prepared vegetables, stirring gently until completely incorporated.

Grease a baking dish and pour the vegetable and cream cheese mixture, spreading it evenly.

Sprinkle breadcrumbs or crushed nuts and Parmesan cheese over the casserole.

Bake in the preheated oven for 30 to 35 minutes until the top is golden and bubbly.

Remove from the oven and allow to cool for 5 to 10 minutes before serving.