Preheat the oven to 180 degrees C/350F and grease an 8 x 8 inch pan.

Place your crushed Oreos and melted butter into a medium sized bowl and stir until all the crumbs are coated.

Tip the Oreo mix into your greased pan and level with a spatula or your hands.

Place the biscuit base into the oven for 9-10 minutes. Then leave to cool slightly whilst you make the cheesecake layer.

Place the cream cheese, egg, sugar and vanilla extract into a large bowl or the bowl of your stand mixer and beat on a med-high speed until light and smooth, about 3 minutes.

Add in the chopped Twix bars.

Mix on low until the Twixes are incorporated. Tip the cheesecake mixture on top of the Oreo biscuit base and smooth until level. Sprinkle the milk chocolate chips on top.

Place in the oven for 30-35 minutes until lightly golden around the edges and the cheesecake has set. To see if the cheesecake has set, tap the edge of the pan and see if it wobbles. If it's done the whole top should move together slightly, if it's not done it will wobble all over.

Remove from the oven and leave to cool completely in the pan.

Once chilled, slice into 9-12 bars and keep in an airtight container in the fridge for up to 3 days.