Crush or blend the Oreos so they’re like coarse sand. I use a ziplock bag and a rolling pin, or put them in my food processor.
Add the melted butter and mix well.
Tip into the base of a large springform cake tin. Press down all over, flattening with a spoon or the flat base of a glass.
Bake for just 5 mins, then set aside to cool.
Make The Filling
Put the cream cheese, double cream, vanilla, peanut butter, sugar, eggs and flour in a bowl.
Whisk until smooth. Don't overmix as this can introduce air into the mix, which can affect the final texture and make it more likely to crack.
Toss the chopped Reese's Minis in the tablespoon of flour, shake off the excess and add to the bowl. Briefly fold through.
Assemble And Bake
Pour the batter into the tin on top of the biscuit base.
Scatter the chopped Reese’s peanut butter cups on top.
Bake for 45 mins to 1 hour until firm but slightly wobbly if shaken.
Transfer to a wire rack and run a knife around the inside of the tin. This is important to stop the cheesecake cracking as it cools.
Allow the cheesecake to cool completely.
Make the ganache
Put the chocolate in a heatproof bowl and melt in the microwave in 30 second bursts, stirring after each burst until just melted.
Add the cream and gently whisk until the whole mixture becomes glossy and smooth.
Spoon the ganache on top of the cheesecake in the centre, so that it doesn’t each the edges.
Scatter the whole chopped Reese’s peanut butter cups and whole Reese’s mini peanut butter cup on top.
Refrigerate overnight.
Serve
When you're ready to serve the cheesecake, run a knife around the inside of the tin and unlock to release the sides. It should then lift onto a board cleanly.
Slice with a sharp knife to serve, wiping between cuts for a neat finish.