Cut your tortillas into chips and spread them out on parchment-lined cookie sheets.Spray with an oil sprayer, being sure to coat the tops of the chips as evenly as possible.In a bowl, mix together the nutritional yeast, garlic powder and onion powder.Sprinkle the yeast mixture over the chips.Bake at 325 F. for 20-30 minutes. This time can vary by oven, so set your timer for 15 minutes and check them every 5 minutes after that. They go from done to burned pretty quickly. So watch them closely. Also, do not bake them until they are completely crispy. They will harden as they cool, and if you bake them until crispy, you will end up with something more like a jaw breaker after they have cooled down.Remove from the oven and allow to cool completely.