I made a triple batch of plain cookies and realized I had added too much sugar...thin, hard and very sweet. Can I make a sort of cake ball with the crumbs?
You could also pop them into your food processor and process until the texture of graham cracker crumbs. Store them in a ziploc or vac pack. When you have a recipe that requires a graham cracker or cookie crust...substitute your cookie crumbs for the graham crackers, Oreos or Nilla wafers the recipe calls for.
If you're not going to use the crumbs immediately make sure they're completely dry before storing. If the crumbs still have some moistness to them...spread them out on a cookie sheet and dry them in the oven for 10-15 minutes at 275-325 like you would for bread crumbs. Once they're cool and dry put them in a ziploc or air tight container. They should last up to about 3 months.