In a small skillet over medium-high heat, combine the bread crumbs and oil. Stirring often, toast until crispy and golden brown. Transfer bread crumbs to a small bowl and mix in the taco seasoning.
Beat eggs in a shallow bowl or rimmed plate.
In a small bowl, combine cream cheese, cheddar cheese and diced jalapenos.
Using a small, sharp knife, either cut a pocket in each breast or butterfly them. If they're especially thick, I like to pound them a couple times with the flat side of a meat mallet to thin them out some first - too thick and it takes so long to cook through that the bread crumbs burn.
Season the chicken lightly with salt and pepper. Divide the cheese filling evenly between the chicken breasts; close with toothpicks if you like.
Dip the chicken in the beaten egg and then the bread crumb mixture, coating each piece completely. You can put them straight into the baking pan, or put a rack in the bottom of the pan first so the bottoms won't get soggy. Bake in a preheated oven 25 to 30 minutes, or until the chicken is cooked through.