First make the syrup. Thinly peel the zest from the lemons, cut them into super thin strips “julienne”. Take one third and pop into a mixing bowl for the sponge, place the rest in a small saucepan and add the sugar plus 4 tablespoons of lemon juice plus 2 tablespoons of water. Bring to the boil and then simmer for 5 minutes until slightly thickened. Remove from the heat and stir in the Limoncello, set aside.
Lightly butter the inside of 6 pudding moulds or ramekins and line the base of each with a little square of baking paper (if you’re cooking your puddings in ramekins or cups and don’t plan to turn them out for serving, skip the baking paper). Set aside.
Cream the butter and sugar in the bowl of a stand mixer until light and fluffy or use an electric hand whisk. Add the eggs, one at a time, whisking well to mix after each addition. Sift in the flour and baking powder together and whisk briefly until just combined. Add 2 tablespoons of lemon juice and gently mix until smooth.
Preheat oven to 100⁰C/212⁰F, steam setting high.
Spoon the syrup between the moulds, top with the sponge mixture and insert an amaretti biscuit into each. Cover each with a piece of pleated foil – press around the moulds to seal but not too tightly as they need enough ‘give’ to rise a little. Put the moulds onto a rack or perforated tray and steam for 25 minutes to cook through. Stand for 5 minutes before turning out and serving with cream, ice cream or custard.
