Cook the bacon in a heavy bottomed cast iron skillet (or an oven proof pan), until it crisps. Remove from the pan and transfer to a paper towel lined plate.
Mix together the cream cheese, 3/4 cup of mozzarella cheese, garlic powder, 3/4 of the diced jalapeños, and 3/4 of the cooked bacon.
Cut the chicken breasts in half to butterfly them open. Sprinkle lightly with salt and pepper. Divide the filling between the two chicken breasts and then secure them closed with tooth picks.
Remove all but about 1 TBSP of bacon fat from the pan and put the pan over medium-high heat. Cook the chicken for about three minutes on each side, then top with the remaining cheese, bacon, and jalapenos.
Place the pan in the oven and bake for 15 to 20 minutes or until the thickest part of the chicken (usually the opposite side of the opening with the filling) reads 165 degrees F internal temperature. Serve immediately.