Cut each pepper in half length-wise and place on a large baking sheet.
Add the ground beef to a large skillet over medium heat. Brown the beef, crumbling as it cooks, until cooked through. Drain the beef and return to the skillet.
Season the beef with the cumin, garlic powder, onion powder, and salt. Stir to coat the meat.
Add the tomatoes, cream cheese, and 1 cup of shredded cheddar to the pan and cook, stirring constantly, until the cheese is melted and everything is well combined.
Spoon the taco mixture evenly between all of the peppers.
Top with the remaining cheddar and place pan in the oven for 10 minutes.
Remove from the oven and drizzle with sour cream and sprinkle with cilantro before serving.
Notes
The mini peppers will still be crunchy after just 10 minutes. If you'd like softer peppers, cover the dish with foil and bake for 20 minutes.