1whole Pineapple cored, sliced into one inch slices
Heat grill to 350 degrees on direct heat
Combine vanilla, orange juice concentrate (defrosted), cinnamon and butter together in a bowl and mix. Put ingredients in a Ziploc bag.
Slice the pineapple and remove the core. Cut pineapple into 3/4 inch slices and put in Ziploc bag with the orange mixture and allow to sit 5-10 minutes, maximum.
Place pineapple slices on the grill and cook for 3-4 minutes. Flip. Grill second side 3-4 minutes.
Right before removing, brush the newly grilled side with the orange mixture from the bag. It will start to sink into pineapple grooves and caramelize. Turn over one last time to brush the orange mixture to the second side and remove from the grill.
You can safely use the orange mixture from the Ziploc bag for basting as you are only marinating fruit, not raw meat. This is not something to ever do with raw meat.