Question: To harden the chocolate on the rainbow cookies after frosting
Options:
put the frosted rainbow cookies back in the fridge  and leave them there for an hour or two, until the chocolate hardens
put the frosted rainbow cookies back in the oven  and leave them there for an hour or two, until the chocolate hardens
Answer: put the frosted rainbow cookies back in the fridge  and leave them there for an hour or two, until the chocolate hardens