Cut the gelatine into broad strips, place in a bowl, cover with cold water and leave to soak for 5 minutes, then drain.
At the same time, bring the cola to the boil in a small saucepan, then remove from the heat. Pour about a quarter of the cola over the gelatine and stir to dissolve, then stir this back in with the rest.
Pour into a bowl, leave to cool, cover and chill for several hours or overnight until set. Arrange the trifle sponges in a deep 20cm trifle bowl, cutting them to fit (or make individual servings). Sprinkle over the rum.
Gently heat the marmalade with the lime juice in a small pan, stirring to blend. Press through a sieve and drizzle over the sponges.
Run a fork through the jelly to break it up into a jewelled mass and spoon this over. For the topping, whisk the egg yolks and sugar in a bowl, then whisk in the mascarpone, and vanilla extract if including.
Using an electric hand whisk, whip the egg whites until stiff. Fold into the mascarpone base. Smooth this over the top of the trifle, cover and chill for several hours. The trifle will keep well for a couple of days.
Decorate shortly before serving with lemon jellies and a scattering of boiled sweets crushed with a rolling pin.
If wished, make decorative sugar shards as in the main picture by placing 1-2 boiled sweets on a baking sheet in a low oven (about 150C/130C fan/gas 2) for 10 minutes until just softened. Carefully pull these into swirly shapes.
|Fresh Lime Juice||2 tbsp|
|Lemon And Lime Marmalade||100g|
|Dark Rum||3 tbsp|
|Cola (not The Diet Kind)||600ml|
|Gelatine Leaves (we Used Supercook)||5|
|Green Boiled Sweets|
|Lemon Jelly Sweets|
FOR THE TOPPING
|2 Tsp,vanilla Extract Optional||1⁄|
|Medium Organic Eggs Separated||3|