Preheat your smoker to 225°F. If you don’t have a smoker, you can use a grill with indirect heat or an oven set to the same temperature.
In a large mixing bowl, combine the softened cream cheese, shredded cheddar cheese, and shredded Monterey Jack cheese. Mix until well combined.
Stir in the diced tomatoes with green chilies, sour cream, garlic powder, onion powder, smoked paprika, and cumin. Season with salt and pepper to taste.
Transfer the mixture to a cast-iron skillet or a disposable aluminum pan.
Place the skillet or pan in the smoker and let it cook for about 30-40 minutes, or until the cheese is melted and bubbly. If using a grill or oven, keep an eye on it to prevent burning.
Once done, remove from the heat and let it cool for a few minutes. Garnish with fresh cilantro if desired.
Serve warm with tortilla chips for dipping.