Preheat oven to 175 C degrees.
Butter a 20x20 cm baking dish and keep aside.
In a bowl, add chopped apples, brown sugar, tsp of cinnamon and lemon juice.
Mix to combine and then transfer to the prepared baking dish.
In a separate mixing bowl, add your topping ingredients (1 tsp cinnamon, brown sugar, oats, flour, salt, and diced cold butter).
Using a fork or pastry blender (or even your fingers), combine the butter into the oat mixture, until you get a crumbed mixture.
Spread topping over apples in a baking dish.
Bake 40-50 minutes, until golden brown and bubbly.
Serve warm with a scoop of vanilla ice-cream and enjoy!