Dessert for two need not leave a full cake asking to be eaten all week. A few baked pear halves, cinnamon apples, or fruit with melted chocolate can fit the evening more comfortably.
Choose a method that matches the time available. If the oven is already on, a small fruit dish may be convenient. If the kitchen is hot or dinner used every pan, fresh fruit and a suitable purchased accompaniment are sensible options.
Portion the dessert in small dishes before serving if that helps you avoid making too much. Keep any perishable remainder chilled and labeled rather than leaving it on the table after the meal.
The pleasure can come from temperature and texture as much as complexity: warm fruit, something cool beside it, and a spoon that reaches both. There is no need to add a third component just because a photograph might look busier with one.