For his fourth birthday, I made my son an Incredible Hulk cake. His hope was for a 3D Hulk, an edible version of his favourite plastic toy. My plan was for a Hulk’s head impressive enough to make up for the fact that he didn’t have any limbs or muscles. Even this limited version proved too much of a challenge, however, and I ended up sticking a plastic model of the incredible one on to a round, green cake. After looking confused, Luca was surprisingly happy with his leaning Hulk, until a candle melted his plastic elbow. There was a birthday girl, too, so two sets of candles were lit, happy birthday sung in two languages and two cakes cut into slices. My green cake with foot marks remained pretty much intact, while the other disappeared square by square into small and large mouths alike. And with good reason: that second cake was what the other mum described as a torta versata con crema, which translates as a “poured cake”, but is best described as two light sponge cakes filled with custard. At first I thought the filling was added after baking, but as I ate my second tender slice, she explained that, after cooking one baked layer of sponge, the custard is spread over it and the rest of the batter poured on top, before the whole thing is baked again. Cake with a baked heart of custard – words as soothing as custard itself. Some of my happiest moments have been in the presence of thick custard or pastry cream; sitting in the old Patisserie Valerie with Dad watching his joy as he ate a custard slice, and breakfast of just-fried doughnuts filled with crema at the port bar in Palermo. The definition of pastry cream in Enciclopedia Treccani is soothing, too – la crema pasticciera (pastry cream) is made with egg yolks, sugar, milk, flour, maybe vanilla or lemon, thickened over heat and used to fill various pastries; the addition of chocolate or cocoa, or soluble coffee, produces crema al cioccolato or la crema al caffè. Soothing, unless, like American journalist and writer Ambrose Bierce, you think custard is “a detestable substance produced by a malevolent conspiracy of the hen, the cow and the cook”. While not malevolent, I have at times felt hostile towards custard – and afraid of all those yolks, which bring such a high possibility of something going wrong. This changed when I started adding flour or cornflour, which, I know, not everyone approves of (and means it is not actually custard). But cornflour is like bike stabilisers for a cook such as myself, reducing risk and ensuring thickness. A few green lemon leaves will give it a touch of the Hulk, although possibly not enough to win the approval of a four-year-old. Sponge cake with heart of lemon custard Prep 15 min Cook 30 min Serves 10 2 egg yolks 70g caster sugar 40g cornflour The zest of 2 lemons 600ml whole milk For the sponge 4 eggs 120g caster sugar 90g melted butter, or neutral oil 220g plain flour 2 tsp baking powder 30ml lemon juice Icing sugar, for dusting Start with the custard. Working directly in the pan, whisk the egg yolks and sugar, then add the cornflour and the zest of one lemon, and stir again. Whisk in 500ml milk, then set over a medium heat and cook, whisking, until the milk comes to a boil and the mixture is as dense as thick custard. Pour into a bowl and set aside to cool. Now make the sponge. Whisk the eggs and sugar for three minutes, then add 100ml milk, the melted butter (or oil), the flour, baking powder and the zest of the second lemon, and whisk again until light. Heat the oven to 180C (160C fan)/350F/gas 4. Butter and flour a roughly 30cm x 23cm cake tin. Divide the cake batter in two – either by eye or by weighing – pour half into the tin and use a spatula to spread it out evenly. Bake for 10-12 minutes. Remove from the oven and set aside to rest for five minutes. Meanwhile, whisk the lemon juice into the now cold custard and then, working carefully, spread it over the top of the cake. Zigzag the remaining cake batter over the top, smooth the surface then bake for 15 minutes. Remove and leave to cool, then invert carefully on to a plate. Dust the top with icing sugar and serve with cream. UK readers: click to buy these ingredients from Ocado