Wash, peel and chop your apples into small chunks, about 1 inch in size. Put them in a large bowl and sprinkle the lemon juice and 2 Tablespoons of white sugar over them. Stir well, and then put them into a 8×8 inch glass baking dish (no need to grease it).
In the same (dirty) bowl you just used for your apples, pour in the rolled oats, salt, and brown sugar. Stir to combine. Microwave the butter and coconut oil in a glass measuring cup for 30 seconds (until just melted). Stir in the vanilla. Pour the mixture over the oats in your big bowl. Stir everything until well combined.
Gently cover the apples with the oat mixture. Bake at 350 degrees F for 60 minutes. Allow to cool for at least 10 minutes before serving. Serve with really good vanilla ice cream.