Mississippi Mud Pie

Preheat the oven to 160°C fan bake.

Base: Place the biscuits in a food processor and process to fine crumbs. Add the butter and pulse to combine well. Tip into the tin and use the back of a teaspoon to press evenly over the base and 4cm up the sides of the tin. Make sure there isn’t a thick edge where the base meets the sides of the tin. Chill the base while you make the filling. 

Filling: Melt the chocolate and butter in a heatproof bowl set over a saucepan of simmering water. Don’t let the base of the bowl touch the water. Remove from the heat and set aside. 

Whisk the eggs, sugar and vanilla together for 5 minutes until very pale and light.

Fold in the chocolate mixture, cocoa and cream until well combined.

Spoon onto the biscuit base and smooth the top. 

Bake for 35 minutes until just firm but still with a little wobble in the centre. Don’t overbake. The cake will rise dramatically while cooking then deflate and crack as it cools. Remove from the oven and cool completely in the tin. Cake can be made 2 days ahead of serving. 

Custard: Combine the sugar, cocoa, cornflour and salt in a medium saucepan. Whisk the egg yolks, milk, cream and vanilla together in a bowl. Whisk about ½ a cup into the sugar mixture to make a thick, smooth paste then whisk in the remaining egg mixture.

Cook over a medium low heat, whisking constantly until the custard starts to thicken on the base of the saucepan. Don’t let the custard boil or you’ll have chocolate scrambled eggs. Immediately remove from the heat and continue to whisk for 1 minute until very thick and glossy. Return to a low heat and cook, whisking constantly for 2 minutes or until very thick. Remove from the heat and stir in the butter and chocolate until melted. Press a piece of plastic wrap directly onto the surface and cover to prevent a skin forming. Cool then refrigerate for several hours or up to 3 days. 

Whisk the cold custard until smooth. Carefully spoon into the centre of the cake, spreading it evenly.

To serve: Carefully run a warm knife around the inside of the tin before releasing the sides. Transfer to a plate and spoon on the softly whipped cream then garnish with grated chocolate. Serves at least 12

Cook's Tip: If you don't want to make the chocolate custard layer, serve the cake with a bowl of softly whipped cream and the following warm fudge sauce.

Fudge Sauce: Place all the ingredients in a saucepan and melt over a medium heat until the sauce is smooth and glossy. Cool until just warm.