When ready to serve pineapple, insert soaked bamboo skewer into each piece of pineapple. Lightly dust each spear with sugar-spice mix. Heat grill to 375 F. Brush grill with a bit of neutral-flavored oil (grapeseed oil works well) and place pineapple skewers down at a 45-degree angle to grill grates; cook for 1 or 2 minutes, or until you have a nice grill mark and the pineapple lifts easily. Lift and replace pineapple at the opposite 45-degree angle to make a cross-hatch grill pattern. Repeat on the other side.