Does "Nuts" have 2 meanings here?
Yes, "nut" has two meanings here. The first meaning refers to "nuts" as a food. "Nuts" as a food are often in fudge (a type of chocolate), which he previously mentions. The second meaning of "nuts" is "crazy people", because he is comparing fudge and all of the ingredients in fudge to a family. Therefore, he is saying that a family has mostly sweet people ("is mostly sweet") and a few crazy people ("with a couple of nuts").