Prepare a grill for medium-low to low heat. Spray a grill tray with holes with cooking spray.
Mix the olive oil and maple syrup together in a small bowl and brush over the peaches and pineapple. Put the fruit cut-side down on the prepared grill tray and cook low and slow, rotating them 90 degrees halfway through, about 5 minutes. Monitor the cooking temperature and keep it low enough so that the maple syrup doesn't burn but browns a little. Set the fruit aside to cool.
To serve, arrange the fruit over scoops of vanilla ice cream, sprinkle pecans all over the top and drizzle with extra maple syrup.