Preheat your oven to 350°F (175°C) and spray a large skillet with nonstick cooking spray.

Brown the ground beef and chopped onion over medium heat for 5-7 minutes until fully cooked; drain excess fat.

Add diced bell peppers and cook for another 3 minutes until softened.

Stir in the fire-roasted tomatoes and chili powder; season with salt and pepper. Simmer for 5 minutes.

In a separate bowl, combine sour cream with additional chili powder if desired.

In a greased baking dish, layer half of the meat mixture followed by dollops of sour cream sauce; repeat layers and top with cheddar cheese.

Bake for 25-30 minutes until golden brown and bubbly.