Preheat oven to 400° F degrees.
Cut apples in half and core centers out with spoon.
With a knife , slice 1/2" slices, not going all the way through across each apple.
Place apples flat side down in a baking dish or skillet.
Melt 1 Tbsp butter and brush apples with butter. Mix cinnamon and sugar together, and sprinkle over tops of apples.
Bake apples for 12 minutes, until soft enough to open slices easily.
Meanwhile, beat 1/2 Cup heavy cream until stiff peaks form. Set aside.
Place 2 cups of granola in a bowl, and pour 1 Tbsp melted butter in bowl and mix well.
Remove apples from oven, and carefully fill slices with granola mixture. Top remaining granola mixture over all apples. Bake another 10 minutes.
Remove from oven, and top with heavy whipping cream and sprinkle of cinnamon. Enjoy!