Preheat your oven to 375°F (190°C).

In a large skillet, heat a drizzle of olive oil over medium heat. Add diced bell peppers and chopped zucchini, and sauté for about 5-7 minutes until tender and slightly caramelized.

Incorporate cauliflower rice and fresh spinach into the skillet. Stir well and allow them to cook for another 2-3 minutes, just until the spinach wilts.

In a separate mixing bowl, combine cream cheese, half of the shredded cheddar cheese, Italian seasoning, salt, and pepper. Whisk until smooth and creamy.

Fold the sautéed vegetable mixture into the creamy sauce, ensuring that each piece is well-coated.

Transfer the mixture into a greased deep casserole dish, spreading it evenly and topping with remaining cheddar cheese.

Place the casserole in the preheated oven and bake for 25-30 minutes until golden brown and bubbly.

Let the casserole rest for 5-10 minutes before serving to allow layers to set.