Grease and line an 8 x 8 inch square pan. Place your crushed digestives into a medium sized bowl and pour the melted butter on top. Mix with a wooden spoon or spatula until all the digestive crumbs are coated with butter.
Tip the biscuit mix into the cake pan and push into all corners of the pan. Level off with a spatula or your hands, both work well.
Place the biscuit base in the fridge for at least 30 minutes.
Once the base is chilled, place the cream cheese and icing sugar into a large bowl or the bowl of your stand mixer. Beat until light and fluffy, about 2 minutes on med-high speed.
Add in the double cream and mix on a med-high speed until smooth and thick.
Add in the 6tbsp of lemon curd and mix until well combined. Pour over the biscuit base and smooth over until level.
Place a few dollops of lemon curd on top of the cheesecake and then, using a skewer, or similar, drag the lemon curd through the cheesecake making glorious swirls :)
Place in the fridge to set for at least 3 hours.
Once chilled and set, slice into 9 or 12 bars depending on how big you want them.
Bars will keep in an airtight container in the fridge for 3 days.