Sugar Free Coffee and Chocolate Slice

For the cake: heat the oven to 200°C (180° fan) 400°F gas 6. Line two 31cm x 39cm|12 1/2" x 15 1/2" baking tins with non-stick baking paper and brush with melted butter.

Whisk the egg whites until they form soft peaks. Add the sugar and beat until stiff and glossy. Set aside.

Whisk together the almonds, powdered sugar and eggs with an electric whisk until light and voluminous. Mix in the flour until just blended.

Gently fold the meringue into the almond mixture, then fold in the melted butter.

Divide the mixture evenly between the tins and spread evenly to cover the entire surface of each tin.

Bake for 5-7 minutes, until lightly browned and just springy to the touch. Cover each with a sheet of non-stick baking paper, invert the tins and turn out. Carefully peel away the paper, turn the paper over and use to cover the exposed sides of the cakes. Cut the cakes down the middle to make 4 strips. Cool the cakes between the paper sheets.

For the coffee syrup: stir together all the ingredient in a small pan and bring to a boil, stirring. Set aside to cool.

For the coffee buttercream: dissolve the instant espresso in the boiling water and set aside.

Heat the sugar and water to a boil in a small saucepan, stirring just until the sugar dissolves. Continue to cook without stirring until the syrup reaches 124°C|255°F on a sugar thermometer. Remove from the heat.

Whisk together the vanilla, egg and egg yolk until pale and foamy. When the sugar is at temperature, reduce the whisk speed to low and slowly pour in the syrup. Increase the speed to medium-high and continue to whisk for about 5 minutes until the eggs are thick, shiny and room temperature.

Beat the butter until soft and creamy.

Steadily whisk in the butter, about 2 tablespoons at a time to the egg mixture. When all the butter has been added, increase the speed to high and beat until thickened and glossy. Beat in the coffee. Chill the buttercream for about 25 minutes, stirring frequently, until it is firm enough to spread.

For the chocolate ganache: put the chocolate in a bowl. Heat the milk and cream to a boil, pour over the chocolate, stand for 1 minute, then stir gently until smooth and glossy.

Beat the butter until smooth and creamy, then stir into the ganache in 2-3 additions. Chill the ganache for about 20 minutes, stirring every 5 minutes, until it thickens and is spreadable.

To assemble the cake: line a baking tray with non-stick baking paper.

Beat the coffee buttercream.

Place 1 cake layer on the paper and brush with coffee syrup. Spread about half the coffee buttercream evenly over the cake. Top with another cake layer and brush with syrup.

Spread the chocolate ganache over the surface and top with a cake layer. Brush with coffee syrup. Spread with the remaining coffee buttercream and top with remaining cake layer. Freeze the cake for about 20 minutes.

For the chocolate glaze: heat the butter to a boil in a small pan. Remove the pan from the heat and clarify the butter by spooning off the top foam and pouring the clear yellow butter into a small bowl; discard the milky residue.

Melt the chocolate in a heatproof bowl over a pan of simmering (not boiling) water, then stir in the clarified butter.

Place the cake on a wire rack over a sheet of non-stick baking paper. Protect the sides of the cake with non-stick baking paper.

Pour the glaze over the top of the cake, using a long spatula to smooth it evenly across the top. Chill the cake until the glaze is set.