Preheat oven to 350 degrees. Spray the wells of a standard size muffin tin with nonstick spray. Roll out dough onto a lightly floured surface, and cut out circles about 2 inches in diameter. Gather and re-roll unused dough and cut additional circles. use the rim of a small plastic cup. Place the circles in the bottom of each muffin well.
Add the apples, sugar, cinnamon, lemon juice, and cornstarch to a medium saucepan. Cook on medium heat, stirring occasionally for about 5-10 minutes until the apples have softened slightly and the juices begin to thicken. Remove from heat.
Add about one tablespoon of the apple filling on top of each circle of pie dough.
In a medium bowl, mix flour, brown sugar, granulated sugar, oats, and salt. Add melted butter and mix until well incorporated.
Add a heaping tablespoon of the streusel topping to each muffin well, and gently pat it down over the apples.
Cook about 20-25 minutes until crumbs are cruncy
