Heat oven to 350 degrees.
Chop up the apples, into medium-sized cubes toss in 1/4 tsp (half the amount) of cinnamon.
Cover the bottom of each muffin cup with apples. Disperse the berries on top of the apples. I usually put 2 raspberries, and one blackberry that is cut in half.
Combine the cup of oats, vanilla extract, rest of the cinnamon, and sugar in a bowl.
Cut the butter into small bits and add to the oats. Use your hands to mix the butter in and clump the oats and sugar together.
Cover the apples and berries in a layer of oats.
Bake for 20-25 minutes.
If you want, dollop a tbsp or two of whipped cream on the side of the cup.