Preheat the oven to 375°F. Combine the apples, granulated sugar, applesauce, flour, lemon juice, and 1 teaspoon of the cinnamon in a large mixing bowl. Stir to thoroughly combine, then scrape into the pie shell. (Depending on the size of your apples, this may make more filling than you need. The apples should rise slightly over the pie shell, mounding in the center.) Combine the almonds, brown sugar, oats, butter, and remaining 1⁄2 teaspoon cinnamon in a bowl. Use your fingers to help break up the butter and mix with the other ingredients. Sprinkle the topping evenly over the pie. Place on the middle rack and bake for 45 to 50 minutes, until the apples are soft and the crust is golden brown. Cool before slicing and serving with scoops of vanilla ice cream.