Here was the problem. I cooked this right before we left for the racetrack. I removed it from the oven, placed foil on top, and walked out the door. When we arrived to the racetrack, the casserole was still hot but the tortilla chips tasted stale. The tortilla chips I used were not stale. I've come to the conclusion that placing foil over the hot casserole caused the chips to become stale/mushy. My question to Blogger World:
What are some ways I can keep food warm, but not cause it to become mushy or stale? The drive to the racetrack is about an hour.
However, the night wasn't a total loss. I did make awesome brownies.