In act 2, scene 1 of Albert Hackett and Frances Goodrich’s stage adaption of Anne Frank’s journal The Diary of a Young Girl, Dussel and Mr. Van Daan, as the question points out, argue. The fight is tied to the cake that Miep brings to the people hiding in their attic. As food is scarce and life is arduous, Miep tries to enliven their spirits by giving them a treat. Anne’s dad, Mr. Frank, is buoyed by the present. “Look at what Miep’s brought for us!” he exclaims. The other attic residents, including Anne’s mom and Mr. Van Daan, are excited as well.
The mood takes a negative turn when Dussel insists that Mrs. Frank cut the cake. According to the ornery dentist, Anne’s mom “divides things better.” This comment does not sit well with either Mr. Van Daan or Mrs. Van Daan. They don’t like what he’s insinuating about the Van Daans. According to Dussel, even though everyone in the attic is in the same dire predicament, Mrs. Van Daan, when called upon to divide the food that they get, inevitably gives her husband a little more.
Mr. Van Daan deescalates the situation himself by giving the knife to Anne’s mom. Right before Mr. Van Daan surrenders the utensil, Anne’s dad turns to Miep and quips, “You see what a little sugar cake does to us? It goes right to our heads.” In other words, Mr. Frank explains the argument between Dussel and Mr. Van Daan by attributing the flare up to the thrill of a sugary treat.