Tiramisu

1. Preheat the oven to 180 C / fan 160 C / Gas Mark 4. Line two baking trays with baking paper. Fit a large, round (1A) nozzle to a piping bag ready for the mix.
2. Separate the eggs into two large bowls and add the extra egg white to the bowl of egg whites.
3. Add half the granulated sugar to the egg whites and using an electric whisk to beat until you have soft, glossy peaks. You should be able to turn the bowl upside down and nothing moves! Set to one side.
4. Add the rest of the sugar to the egg yolks and beat with an electric whisk until the mix pales and goes fluffy – it should increase in size.
5. Add a small amount of the egg white to the egg yolk mixture and fold in with a metal spoon, to loosen the mixture. Add the rest of the egg whites and fold gently until almost combined.
6. Mix the gluten free flour, xanthan gum and baking powder in a bowl and then sift into the egg mixture. Fold in carefully until there are no streaks of flour – make sure you're folding not beating the mixture. You want to retain as much air in it as possible!
7. Spoon the mixture into the piping bag and then pipe the mixture onto the baking sheets into thick lines, approximately 3.5 inches long. Make sure they're all around half-an-inch apart so they don't spread into each other.
8. Dust the fingers liberally with icing sugar (don't worry about excess on the tray!) and then bake for 15-18 minutes until slightly golden round the edges and crackled.
9. Remove from the oven and cool on a rack before eating. Keep in an airtight container for up to 3 days or freeze.
10. Make the espresso and allow to cool to room temperature.

To make the cream layer:

1. Add the double cream to a large mixing bowl and sift in the icing sugar. Using an electric whisk, whip until it forms soft peaks. Be careful not to over-whip (it can change fast!) – you don't want the cream to be too stiff.
2. Drain any excess liquid from the mascarpone cheese then add to the cream. Beat with the electric whisk for a minute or until combined with no lumps. It should still be quite thick but spoonable.

To construct the dessert:

1. Pour the espresso into a large, shallow bowl and add the Tia Maria. Get your serving dish ready (I used a 20cm x 30cm rectangular dish).
2. TOP TIP: I find it helps to work out how the sponge fingers best fit in an even layer BEFORE soaking them. In my dish I wanted them all facing the same way, so had to cut some of the fingers in half before soaking)
3. Working one-at-a-time, dip a sponge finger into the coffee, quickly turn it over then remove from the coffee and place in your serving dish. These absorb the coffee VERY quickly so do NOT leave them to soak! Keep going until you have created an even layer in the serving dish.
4. Spoon half the cream mixture over the top of the sponge fingers and then use a palette knife to smooth it into one even layer.
5. Repeat steps 5 and 6 with the remaining sponge fingers and then the remaining cream, so you have 2 more layers. Liberally grate the dark chocolate over the top and then place in the fridge for at least 4 hours. Don't skip this step, I know it's hard – once chilled, serve and enjoy!