This recipe couldn't be simpler. It is so simple I'm not even going to write an official recipe.
Get a fresh pineapple.
Depending on the age of the pineapple, you can cut out the core if it is too tough. Otherwise, leave it in as I did here.
Mix together brown sugar and cinnamon.
Put the pineapple on the grill for about 3 minutes.
Flip. Sprinkle side one with sugar mixture.
After about 3 minutes, flip again. Sprinkle side two with sugar. Cook for another 3-4 minutes until the pineapple softens and you have some grill marks.
Flip and finish cooking.
Serve as is or with whipped cream or ice cream (vanilla or coconut is delicious)