1) Preheat the oven to 180C/Gas 4. Place a paper baking case in each cup of a standard muffin pan.
For the biscuit base:
1) In a bowl, combine the digestive biscuit crumbs, sugar and melted butter until the crumbs are moistened.
2) Press a layer of the biscuit mix into bottom of each baking case in the muffin pan and then put 1 peanut butter cup into the centre of each.
For the filling:
1) Beat the cream cheese with a handheld electric mixer until fluffy. Add the sugar, flour and vanilla, beating well.
2) Add the eggs, 1 at a time, beating well after each addition.
3) Spoon the cream cheese mixture into the baking cases over the peanut butter cups and biscuit base.
4) Bake until just set, about 20 mins. Allow to cool completely before serving.