In the restaurant we use a large shallow cheesecake tin approx 25cm in diameter which will give about a dozen portions.
Here's what we use; 400g pack of plain digestive biscuits, 125g butter, 25g brown sugar, 2 tubs Philadelphia approx 600g, 50g white sugar, 100ml double cream and a good measure Baileys Irish Cream.
In a bowl (not glass!) bash your biscuits to a fine crumb. I pound them with the end of a heavy rolling pin.
Melt the butter and brown sugar together. A blast in the microwave on half power is just the job.
For the topping put the cream cheese, sugar and cream into a bowl and whisk together until the mix is incorporated and slightly thickened. Now add the Baileys (about half a glass) and gently whisk into the mix. Taste, and add more Baileys if needed. You should be able to taste the Baileys, but don't overpower it.
Spread the cheesecake mix over the top of the set biscuit base and return it to the fridge. I like to give the whole thing a couple of hours in the fridge before serving.
To serve, cut into wedges, sprinkle a little cocoa powder, pour some cream and, above all, enjoy!