Measure out the butter and melt in a saucepan. Pour it into the bowl with the cookie crumbs and using a wooden spoon combine the ingredients together until the mixture resembles wet sand.
Pour the crumbs into a lined 8″ or 20cm cake pan and using the back of a spoon press it down into an even layer. Place the cake pan into the fridge for the base to set while making the filling.
While the chocolate is melting pour the cream into a mixing bowl and using a hand mixer or whisk whip the cream until it forms soft peaks. Set to the side.