Baked Alaska flambe

Over medium heat dissolve the sugar in the water until clear.

Off the heat, stir in the instant coffee powder, then the chocolate; cover and set the pan over simmering water to melt.

Set a bowl over ice and water and beat the heavy cream until doubled in volume, past the ribbon stage.

Beat the chocolate over the ice until smooth and shiny, then fold it into the whipped cream.

Turn the mixture into a mold, cover with plastic wrap and freeze two to four hours.

Butter the cake tin liberally, flour it heavily and line the base with parchment.

Beat the eggs, sugar, vanilla and grated lemon rind with a pinch of salt for about ten minutes to the ribbon stage, doubled in volume and pale yellow.

Sift in a quarter of the flour and fold rapidly six to eight times, rotating the bowl; repeat with the remaining flour.

Fold in the tepid melted butter, alternating with the flour, without deflating the batter.

There is no baking powder in this cake, so fold with enough speed and delicacy that the batter keeps its original volume.

Pour into the tin, spread to the edge, bang lightly on the table and bake on the middle rack 25 to 30 minutes, five degrees Fahrenheit below the book temperature.

The cake is done when the top is spongy and a hairline of shrinkage shows around the edge of the tin; cool ten minutes or more, then turn out onto a rack and cool completely.

Slice the cake into half inch layers.

Piece the cake layers together and sprinkle with the cognac; cover tightly with plastic wrap and set aside.

Beat the egg whites to soft peaks, add the salt and cream of tartar, then add the caster sugar a tablespoon at a time, half a minute between each three tablespoons, and the vanilla; beat to shiny stiff peaks.

Set the ice cream mold in a basin of tepid water, run a knife around the edge and turn it out onto the cake, leaving an inch border of cake around it.

Cover the whole thing with meringue about one inch thick to insulate the ice cream from the heat, striating it vertically with a spatula and raising a peak on top.

Wash out half an eggshell, cut the rim and insert it crater-like into the peak.

Sieve icing sugar over the meringue and brown it lightly, in a hot oven or with a torch.

Heat the cognac in a pan, pour it into the eggshell and light it so it runs down the sides.