Preheat the oven to 350 degrees F and spray an 8X8 baking pan with non-stick cooking spray.
In a large mixing bowl, add the apples, sugar, lemon juice and 1/2 tsp of the cinnamon. Mix to thoroughly coat the apples with the mixture.
Pour the coated apples into the baking pan.
In a separate bowl, combine the brown sugar, oats, flour, salt and 1 tsp of cinnamon. Stir to combine and then cut the butter into this mixture. You can do this with a pastry cutter or 2 forks to combine the butter with the mixture.
Then spread the topping over the apples in the baking pan. Bake for 40-50 minutes until the mixture is bubbly and the top is golden brown.