Preheat the oven to 375°F (190°C).
In a large skillet over medium heat, cook the ground beef, onion, and garlic until the beef is browned and the onion is soft.
Add in the cauliflower rice, diced tomatoes, chili powder, cumin, salt, and pepper. Cook for another 5 minutes until the cauliflower is tender.
In a mixing bowl, combine the cooked beef mixture with softened cream cheese. Stir well to incorporate.
Arrange the halved bell peppers in a baking dish and spoon the beef and cream cheese mixture evenly into each pepper half.
Top each pepper with shredded cheddar cheese.
Cover the dish with foil and bake in the preheated oven for 25 minutes.
Remove the foil and bake for an additional 5-10 minutes until the cheese is melted and bubbly.
Garnish with fresh chopped cilantro and serve hot.