Cambridge cake

Whisk the eggs, sugar and vanilla together over a pan of almost simmering water for four to five minutes, until thickened and warm to the touch.

Beat at medium speed until tripled in size and at the ribbon stage, eight to ten minutes.

Sift a quarter of the flour and salt over the eggs and fold it in quickly, thoroughly and gently, lifting the egg up over the flour; repeat with the rest.

Temper the melted butter with some of the flour and egg batter, then fold it back into the eggs.

Pour into a greased and parchment-lined cake pan.

Bake at 350F for 30 to 35 minutes.

Second genoise: heat the clarified butter with the vanilla extract to around 110F.

Heat the eggs and sugar over heat until just lukewarm, stirring constantly, then beat until tripled in size and at the ribbon stage.

Mix the sifted cake flour with the cornstarch.

Whisk a scant cup of the egg mixture into the clarified butter; fold half a cup of the flour mix into the remaining egg mixture and repeat until the flour is gone, then fold the butter mixture in.

Bake in an eight-inch pan at 350F for 25 to 35 minutes, until golden brown and shrinking from the edges of the pan.

Turn out onto a cooling rack.

Bring the sugar and water to a simmer in a small saucepan, swirling; once the sugar has dissolved, cover and boil to the softball stage, 235 to 245F.

Whip the six yolks and two whole eggs until combined.

Stream the hot sugar syrup into the egg mixture to cook it, beating until cool; more than five minutes.

Beat the pound of softened unsalted butter until creamy, then add it to the eggs two tablespoons at a time with the paddle attachment.

If the buttercream goes grainy, add more butter; beat it over a bowl of ice cubes until it reaches a spreading consistency.

Flavour with the coffee, the rum, and the vanilla extract, and beat in the melted unsweetened chocolate.

Refrigerate the buttercream until it is a spreading consistency.

Stir the sugar into the very hot water with the rum until dissolved to make the imbibing syrup.

Split the cooled cake in half horizontally.

Dribble the syrup over the cut cake, not too generously.

Spread half a cup of buttercream over the bottom layer and shimmy the top layer on, cut side up.

Spread three quarters of a cup of icing evenly over the top and sides as a crumb coat; about half a cup went on the sides and a cup on top.

Melt the unsweetened and sweetened chocolate together, covered, over a pan of water held just under a simmer, about five minutes, then stir until cooled.

Spread the chocolate on wax paper in two strips three and a half by thirty inches; chill to just setting, then trim to two twenty-seven inch strips two inches high.

Peel the wax paper away and stick the chocolate strips around the side of the cake as walls, patching problem areas.

Cut an eight-inch strip from the remaining chocolate for the top and form the bow.

Pipe the remaining chilled buttercream around the cake.