Heat oven to 350 degree F. Coat six 1-cup ramekins with nonstick cooking spray.
In a large bowl, combine pears, peaches, plums, sugar and cornstarch; stir to combine.
Mix granola and butter.
Sprinkle 1 tablespoon of the granola in the bottom of each ramekin, followed by 1/2 cup of the fruit mixture. Sprinkle 1/2 tablespoon granola over the fruit.
Layer on an additional 1/2 cup of fruit and top with 1/2 tablespoon granola.
Bake at 350 degree F for 40 minutes. Remove from oven and cool for at least 15 minutes. Serve warm or at room temperature.