Crush the biscuits by putting them in a large, strong, plastic food bag and bashing with a rolling pin or food processor and blitz.
Tip the biscuit crumbs into a bowl. Melt the butter with the syrup or honey in the microwave, then stir into the biscuits.
Press into the base and up the sides of a 23-25cm round tin and chill.
Break up the two chocolate bars and put in a large bowl.
Melt in the microwave for 2-3 mins on medium, stirring halfway through.
Add in the vanilla extract, then sift in the icing sugar.
Whip the cream until it just holds its shape, then fold into the melted chocolate.
Pour into the prepared tin and smooth the top.
Chill for at least 2 hour or overnight is ideal.
Leave the tart at room temperature for 30 minutes.
Remove the tart from the tin and slide it onto a flat plate.
Top with a raspberries then dust lightly with icing sugar.
Serve with extra raspberries on the side.