Lay the pineapple slices on a baking tray and grill for 4 minutes.
Turn and sprinkle the other side of each pineapple slice with 1 teaspoon light brown sugar. Grill until the sugar is bubbling and the pineapple is heated through.
Meanwhile, mix the yoghurt with the remaining 1 teaspoon sugar and the cinnamon.
Plate up the pineapple and garnish with a tablespoon of the cinnamon yoghurt and chopped fresh mint.