This Just in from Honu

It seems that Honu is an artist. She took a screen capture of Steve and Danno sharing a good joke, added Christmas gifts, a Christmassy border, and a greeting to create a wonderful Christmas card. In case your Hawaiian isn't up to snuff, the greeting reads, "Merry Christmas & Happy New Year," but you'd already figured that out, hadn't you?
This isn't a challenge, since I don't know the answer, but can anyone tell us the name of the episode in which the Dynamic Duo shared that good joke?
Many thanks, Honu, for sharing this with us.