To make the graham cracker crust, preheat oven to 375 degrees. To make the crust, mix together graham cracker crumbs, sugar and melted butter in a bowl until well blended. Next, press the mixture into a 9 in pie pan. Bake for 7 minutes, then set aside to cool.
To make the cream cheese filling, preheat oven to 350 degrees. Using a mixer, cream together the cream cheese and sugar. Make sure to scrape down the bowl and mix again to ensure its mixed well. Next, add milk, beaten egg, lemon juice and vanilla. Beat until all ingredients are blended well and it is light and creamy. Pour the cheesecake filling on top of the cooled off crust. Set aside.
For the topping, mix together sugar, oats and flour in a bowl. Use a pastry cutter or two forks to mix the cold butter into the oat mixture. Mix until the mixture resembles coarse crumbs. Sprinkle this mix over the top of the cheesecake filling. Bake the cheesecake at 350 degrees for 25 minutes. Let cool before slicing.
