Preheat the oven to 400°F (200°C).

In a small bowl, mix the softened cream cheese, shredded pepperjack cheese, chopped bell pepper, onion, garlic powder, and onion powder until well combined.

Carefully slice through the middle of each chicken breast lengthwise, creating a pocket without cutting all the way through. Leave about half an inch on each end unsliced to prevent the filling from falling out.

Stuff each chicken breast with the cheese mixture, dividing it evenly. Secure the edges of the chicken by pinning them shut with toothpicks or skewers at a diagonal angle. Any extra filling can be spread over the chicken breasts.

Combine the cumin, garlic powder, chili powder, salt, and pepper to create the dry rub. Sprinkle the dry rub over both sides of each chicken breast.

Heat olive oil in a large oven-safe frying pan over medium heat. Sear the chicken breasts for about 4 minutes on each side, ensuring they do not burn.

Immediately transfer the pan to the preheated oven or place the chicken in an oven-safe baking dish. Bake at 400°F (200°C) for 15-18 minutes or until an instant-read thermometer inserted into the thickest part of the breast reads at least 165°F (74°C).

Remove the chicken from the oven, cover the pan with foil, and let it rest for 5 minutes before serving.