You could describe an icebox cake as being somewhere between a trifle and a cheesecake. This version uses Lady Fingers or sponge fingers, lightly dipped in lemon and Limoncello, which helps turn them into pillows of soft zingy sponge. If your store cupboard is lacking in Limoncello, simply replace with more lemon juice.
Line the base and sides of an 8” loose bottomed square sandwich tin with cling film.
Zest the lemons and leave to one side until needed.
Juice the lemons to yield approx 150ml
In a small bowl, mix together the lemon juice and Limoncello.
In a large separate bowl, mix together the mascarpone and icing sugar until well combined.
Add the double cream, half at a time, and mix to a thick spreading consistency. Do not over mix.
Add the lemon zest and lemon flavouring – to taste. Mix until well combined.
Build the cake
One by one dip, but not soak, approx 13, depending on their size, of the sponge fingers into the lemon juice mix, then place them evenly on the bottom of the cake tin. Cutting the sponge fingers down to size if needed. Any offcuts can be used to fill in any gaps.
Spread a quarter of the mascarpone cream mix, evenly over the top of the sponge fingers. Repeat this process twice more.
Using your favourite piping nozzle, decorate with the remaining mascarpone mix and a few remaining, none soaked, sponge fingers.
Place in the fridge to set for a few hours. Overnight is best.
To serve
Remove from the tin and carefully slide the cake onto your favourite serving dish. Will keep for a few days in the fridge.
Notes
The sponge fingers will gradually soften as the cream filling starts to set.