Preheat your smoker or pellet grill to 250 degrees F. Use a mild fruitwood like apple, peach, or cherry.
Trim away any excess fat from the chicken breasts, then with a sharp knife, make a 3 to 3-1/2-inch long slit into the side of the breast, halfway deep. Do not cut all the way through. We are simply making a pocket for the filling.
Next, combine the cream cheese with diced jalapenos, chives, shredded cheddar cheese, oregano, and chili powder. Add a pinch of salt and black pepper to taste.
Scoop around 1/2 cup of mixture into each pocket and close them gently.
Wrap each chicken breast with 4 slices of thin bacon slices.
Place directly onto the grill grates, close the lid, and cook for 90 minutes or until chicken reaches 165 degrees F. Remember to check all the breasts in the thickest area with an instant-read thermometer before removing them from the grill.
Once the jalapeno popper stuffed chicken breasts are cooked through and the bacon has a nice golden brown color, it is time to take them off the grill.
Place them onto a serving platter or clean cutting board and let them stand for a few minutes to set up.
Serve them whole, or slice them in half for smaller servings.
Store leftovers in an airtight container in the refrigerator for up to 3 days. Reheat in a 325-degree oven until warmed all the way through.