I will reveal the correct answer after 40 responses.
Here it is:
A father and sun are playing a game of chess on their patio. The moonlight is shining down upon the chessboard, creating a sort of "woosh" sound as the players play their game. The wife/mother stands in the kitchen window watching them play their game with a dirty dish rag in her hand, shouting at the two of them to finish their "silly little game." The husband makes a "hafka" symbol with his hands, and within 5 minutes, his wife brings out a fresh batch of homemade chocolate chip cookies for the two to eat. "The two of you take all the time you need now" she says to the two of them. The son, sitting there, speaks up against the whooshing and says, "but Dad, how did she know about the cookies?" The father winks, and makes the hafka symbol again.
How did he know this would get her to make cookies?