Preheat the oven to 425° F (400°F for dark muffin tins).
Take out a standard 12 cup muffin tin. (I did not grease it but some recipes say to spray with baking spray). Set aside.
Take out the pie dough and roll it out or just open it out. Using a circular plastic lid or cookie cutter, cut out 4 " circles of dough and press one circle into each of the muffin holes. Press down into the bottom and up the sides to the rim of each muffin hole. Don't go over the rim of the hole.
In a medium bowl, whisk together the flour, sugar, alternative sugar if using, and cinnamon. Stir in the lemon juice until mixture is moistened. Toss in the diced apple and stir together until the apples are coated with the mixture. If using, stir in the chopped nuts or cranberries.
Place dots of butter nearby for adding into the mixture as you spoon it into each muffin hole. Spoon mixture evenly into each hole, dotting with butter throughout.
Mix up streusel ingredients until crumbly but not a paste. Sprinkle each mini pie with streusel. Make sure the entire top is covered in a nice pile of streusel.
Place pies in oven for 18 - 20 minutes until crust is golden and top slightly browned.
Remove from oven after testing apples with toothpick to make sure they are tender.
Place muffin tin on cooling rack. Wait 15 minutes before removing pies from muffin tin. Continue to cool on rack. Serve or store for 3 days in covered plastic storage container or freeze for two months.