1 x 125grampacket of plain biscuits(vanilla wine or digestives)
1 1/2teaspoonsvanilla extract
Using a food processor blitz the biscuits until they are fine crumbs. If you don't have a food processor, put the biscuits in a snaplock bag and smash them up using a rolling pin. Stir through the sugar and melted butter. Tip the mixture into a 23-25cm pie/tart dish (one with a removable base if you have one) Press firmly into the tin and up the sides using the back of a spoon or your hands. Put in the fridge to set while you make the filling.
Add all filling ingredients to a large mixing bowl and using a handheld or stand mixer fitted with the whisk attachment, beat on high speed until soft peaks form.
Spoon the filling into the base and spread out evenly using a spatula. Chill in the fridge for 30 minutes before topping with topping with strawberries and blueberries. Dust with icing sugar immediately before serving.
Store the tart in the fridge until you are ready to serve. It can be made one day in advance and leftovers will keep in the fridge for 2-3 days.
Instead of one large tart, you can also make this in mini tart dishes or in jars for individual portions.