Mix flour, sugar, salt in a bowl. Cut in cold butter. Break up butter and slowly add cold water. Divide into two discs, wrap in plastic wrap, and place in fridge for 30 minutes.
Apple Pie Filling
Core, peel and chop up apples. Add to medium sauce pan. Stir in sugars, salt nutmeg and cinnamon. Place on medium heat and cook until juices fall to bottom of pan. Add in flour. Continue to cook and stir occasionally for 5-10 minutes, until thickened.
Pour out filling onto cookie sheet to cool while you roll out your pie crust.
Topping
In a medium size bowl, melt the butter
Add the remaining ingredients and stir until fully incorporated.
Assemble
Preheat the oven to 375 degrees
Roll out all the crust and cut with a large circle cookie cutter. Should make about 14 circles.
Spray a muffin tin with non-stick spray and press 1 dough circle in each muffin cup.
Scoop large spoonfuls of apple pie filling into each cup.
Cover with the oat topping.
Place pies in the oven and bake for 30-35 minutes until lightly golden brown. Remove, allow them to cool, and set for 2 hours before enjoying. You may need to use a small sharp knife to cut around the edges of the mini pie to remove from the muffin tin.