Position one oven rack at the lowest position available. Take one or two sheets of foil and line this rack with it. This will catch all the drippings from the tortillas and make this process mess-free!
Preheat the oven to 375F and place the top oven rack in the middle position, making sure there is at least 4” of room between that oven rack and the next one. I often remove one rack and have the one at the bottom lined and the top one in the middle.
Get the tortillas ready:
Place 4 corn tortillas on a plate, and microwave them for 15 to 20 seconds to warm them up and make them pliable. Once warm, put them on top of a baking sheet and warm up the other 4. I like to warm 4 tortillas at a time and bake 8 at a time.
Spray or lightly brush oil on both sides of all the corn tortillas with cooking spray.
Bake them crunchy:
Pull the oven rack out, if possible, and using tongs, drape each tortilla over two bars of the oven rack.
Bake, for 8 to 10 minutes until the tortillas are golden and crispy. With the tongs, remove them from the oven onto a baking sheet.