Preheat the oven to 400 degrees F. If you’re using more than one baking sheet, place one rack in the lower third of the oven and another in the other third. Avoid placing the lower rack in the lowest position so that the tortillas don’t burn.
Arrange the corn tortillas in a single layer on a large baking sheet. If there’s not enough room, use two baking sheets. Light coat one side of the tortillas with cooking spray and sprinkle with salt. Flip over the tortillas and repeat with additional cooking spray and salt.
Bake the tostadas for 5 to 6 minutes, then flip them over and bake until golden brown and starting to harden, another 5 to 10 minutes. Watch them carefully so they don't burn! If you’re using two baking sheets, rotate them to the opposite oven rack halfway through baking.
Cool the tostadas to room temperature. They’ll crisp up further as they cool down. Serve!
Notes
Please note that I am not a medical or nutritional professional. I provide nutritional information for my recipes as a courtesy to my readers. It is calculated using the built-in recipe card calculator. While I attempt to provide information that is as accurate as possible, you should calculate the nutritional information independently before relying on it.