Prepare the cookie crumbs. You can use the food processor, or you may break up the cookies by putting them in a sturdy bag and rolling them with a rolling pin. Mix cookie crumbs with cocoa and salt in a small bowl. Have cookie mixture ready next to popper, close to stove. Have bowl ready to put popcorn in.
Put popping oil, popping corn and sugar into the popper. Use Medium/High heat. Popping should start in about 2 minutes. Remove from heat when popping almost stops.
Quickly open lid and pour half of the cookie mixture over the hot popcorn; then close lid and continue stirring (no heat) until mixed. Add in remaining mixture, close lid and continue stirring until thoroughly mixed. Pour into a large bowl. Break up 10 - 12 cookies into odd size pieces and add to the popcorn in the bowl. Mix lightly. Cool and store in an airtight container.