"Cancer topped off with whipped cream"
An expression used to define something terrible being brightened up by some funny, wholesome or amazing action.
For example: When "shit hits the fan" and your day can't seem to get any worse, your best friend or co-worker the most hilarious thing to brighten up your day.
You've been feeling sick, had a terrible day at work and have to do a few hours overtime.
You find out you and your favorite co-worker are the only ones left at work for the rest of the time.
"Man, this day is kanker met slagroom."