Easy Apple Crumble

Grocery List Filling 4  Granny Smith Apples (or whatever apple you have on hand) 1/2 cup  brown sugar2 tbsp lemon juice (or water)1/2 tsp ground cinnamon Crumble 1 cup cup rolled oats / oatmeal (quick cooking is ok)1 cup flour1 cup  brown sugar 1/2 tsp baking powder1 tsp cinnamon powder1/2 cup / 125g unsalted butter, meltedPinch of salt How to make it Preheat oven to [...]