1. Cream together 3 tbs of butter and 2 tbs brown sugar along with white sugar.
2. When creamy, add milk and beat.
3. In another bowl mix together oats, salt, baking powder, baking soda and flour.
4. Add this to the butter mixture and beat until incorporated.
5. Line a tray or loaf tin with butter paper.
6. Grease it with butter.
7. Transfer the cookie dough into the pan and press to get an even layer.
8. Preheat oven to 180C.
9. Bake the cookie for 15-20 minutes or until the top is golden in colour.
10. Remove from oven and allow it to cool completely in the pan it self.
11. Once cool, crumble the cookie with your fingertips into a bowl.
12. Add 1 1/2 tbs of butter and 3/4 tbs of light brown sugar to the crumbs.
13. Mix with your finger tips until there are no large chunks of the cookie left.
14. Grease a 7" pie dish.
15. Transfer the cookie crust to the pie dish.
16. Press it with the back of a spoon so that it forms an even crust and lines the whole dish.