Preheat oven to 375°

Split the chicken breasts in half lengthwise to make 4 filets, about 1/2" thick each

Season breasts with salt and pepper and lay them side by side in lightly greased pyrex dish 

Slice cream cheese into 1/8" slices, placing a slice of cream cheese over each breast, spreading slightly to cover. Spreading with a fork can help to distribute the cheese evenly, which will be easier if your cheese is at room temperature.

Sprinkle cheese with chili powder, cumin or fajita seasoning to taste.

Cut jalapeños in half and remove stems. If you want a milder dish remove seeds and membrane with a small spoon (wash your hands afterwards!), if you like a bit more spice you can leave the seeds and membrane in tact. Quarter and flatten with the palm of your hand, dice or thinly slice the peppers, and lay them on top of the chicken breasts and cream cheese.

Cover with shredded cheese. You may add more or less to taste but don't skimp out as the cheese layer helps the chicken not to dry out.

Bake in oven for about 25 minutes or until chicken reaches 165°