Pre-heat the oven to 375° F.
Wash, core, peel, and slice the apples into a large bowl.
Add butter, sour cream, and lemon juice to the apples.
Then mix in the sugar, brown sugar, and salt.
Stir in the corn starch and cinnamon 'til everything is mixed well.
Pour the apple mixture into an 8"x8" or 7 to 9-inch baking dish and set aside.
Mix together the oats, flour, brown sugar, cinnamon, and nutmeg in a separate mixing bowl.
Using a pastry blender, cut the butter into the oat mixture until you have a very crumbly mixture.
Crumble the topping over the apples in the baking dish.
Bake at 375°F for about an hour, or until the top is a deep golden brown.
Remove the crisp from the oven and allow it to cool.
Serve while slightly warm with vanilla ice cream or whipped cream.