Preheat oven to 400°F (200°C).
Slice pineapple in half lengthwise, including the stem and leaves. Using a paring knife, cut around inside border of each half without cutting through rind. Carefully remove flesh from each half; set pineapple halves aside. Remove and discard core from pineapple flesh; cut remaining flesh into cubes. Place in medium bowl with bananas, 1/4 cup (60 mL) of the granola, maple syrup and pumpkin pie spice.
Toss fruit mixture until well mixed; spoon into hollowed pineapple halves. Sprinkle remaining granola over top. Place hollowed pineapple halves on a baking sheet.
Bake in centre of preheated oven until fruit is slightly softened and granola on top is crisp, about 15 min.
To create some drama, forgo the baking and add some heat by flambéing the fruit. Omit granola from fruit mixture. Heat 1 tbsp (15 mL) butter and fruit mixture in medium skillet; sauté over medium heat until slightly softened. Pour in 2 tbsp (30 mL) fruit or nut liqueur, such as Triple Sec or Amarillo); slightly tip pan toward gas flame, if using gas stove. If using electric stove, use barbecue lighter to ignite liqueur. Let stand until flame goes out (when alcohol has burned off). Layer flambéed mixture and 1/4 cup (60 mL) granola in hollowed pineapple halves; sprinkle remaining 2 tbsp (30 mL) granola on top.