Line a baking tray with baking paper, on the side and on the bottom, Spray or apply canola oil on the surface of the baking paper
If you have a food processor, place the biscuits in it and blitz until it has fine crumbs. If you don't have a food processor, add the biscuits to a zip lock bag and crush it using a rolling pin
Add in the melted butter into the biscuit mixture and blitz for further 20 seconds, until well incorporated and resembles like sand
Add the biscuit mixture into the prepared pan and spread it on the base and on the side of the pan using your hands
Use a glass or anything that is verticle to press the crumb neatly on the sides and flatten the base ( make sure this base and sides are well compact, as it is essential for it to stick together when unmoulding)
Freeze the base in the freezer for 1 hour