For the crust: Add the graham cracker crumbs, melted butter and cocoa powder to a mixing bowl and mix together well.
Press mixture firmly into the bottom and around the edges of a tart tin (rectangle 13 3/4 x 4 1/2 inches or circle 9 1/2 inches). Place in the fridge to chill.
Chop the unsweetened chocolate bar into small chunks and combine with chocolate chips in a bowl. Set aside.
Heat 1 cup heavy cream and 2 tablespoons confectioners' sugar gently in a saucepan until just hot, but not boiling. Pour over the chocolate bowl and leave for a couple of minutes to melt, then stir gently until the chocolate has dissolved.
Remove crust from fridge and spoon the drained morello cherries all over the base.
Pour the chocolate on top and smooth down. Place back in the fridge to set for 2 hours.
Once chilled you can slice and serve with a spoonful of the whipped cream, and decorate each slice with a few fresh cherries.
Before adding finishing touches to the tart, dip the fresh cherries into melted chocolate and let them set in the fridge. Once the tart is finished, top it off with the chocolate dipped cherries and a swirl of whipped cream for an extra special dessert.
Per Serving: 714 calories;60.7 g fat;
48.5 g carbohydrates;
8 g protein;
128 mg cholesterol;
245 mg sodium.