Quarter the pineapple lengthwise and cut out the stalk. Cut the fruit quarters into thin slices.
Heat butter in a frying pan. Fry the pineapple for about 2 minutes. Sprinkle with sugar and caramelise lightly. Deglaze with rum. Stir in lime juice and vanilla sugar.
Arrange pineapple with yoghurt and lime-rum sauce. Decorate with mint to taste.
TIP: Experienced cooks flambé the pineapple. To do this, light rum with a stick lighter directly after extinguishing. But please be careful and not in a Teflon-coated pan!