Using up an unwanted box of Rice Krispies by buying two bags of marshmallows to make a large quantity of yummy Rice Krispies squares.
Trying to save time by doubling the recipe and cooking the whole quantity at once.
Lesson: Make ONE BATCH AT A TIME. Y'see, what the recipe on the bag of marshmallows doesn't tell you is that making Rice Krispies squares is like wrestling an Evil Blob Monster from Planet Snapkraklpopzor. And doubling the recipe is like wrestling an Evil Blob Monster from Planet Snapkraklpopzor that's TWICE AS FREAKING HUGE!
I think the most fun part was when I freaked out and screamed "AAAGH!! MUSTGETITALLINTHEPANBEFOREITCOOLSDOWNAND
You've been a great audience. I'll be here all week. Try the Rice Krispies squares. There's plenty!