Sponge Cake: put the eggs (at room temperature) and the sugar in a bowl and beat them with an electric whisk until you obtain a soft, smooth mixture, then carefully stir in a sachet of saffron to “bestow” them with some colour. Gradually pour in the flour and baking powder, stirring carefully from bottom to top.

Put the light, fluffy mixture obtained into the cake tin, which has been buttered and “sprinkled” evenly with a little flour, and cook it in a preheated oven at 180 °C for approximately 30 minutes. Check, from time to time, to see that it doesn’t brown too much; after 20 minutes (not before otherwise the cake won’t rise) cover it, if necessary, with some kitchen foil. After half an hour see if it is done by sticking a toothpick in: if it “comes out” nice and dry the cake is ready, if not leave it in the oven longer.

Pastry Cream: bring the milk to the boil with the vanilla pod and the lemon rind, and then leave it to cool. In a small, deep pan beat the egg yolks and the sugar well, then add the flour, a little at a time, stirring carefully. Very slowly pour in the cold milk – after having removed the lemon rind and vanilla pod from it – and mix it in thoroughly. Put the mixture back over the heat and stir continuously with a whisk; as soon as it begins to boil remove it from the heat. Wait for it to cool down completely before mixing it with the whipped cream, once more stirring from bottom to top, and now you’ll have the… Chantilly Cream.

Syrup: bring the water to a boil in a small saucepan, add the sugar and stir until it has completely dissolved. With the pan still over a low heat, add the orange juice and leave the syrup to reduce for 7-8 minutes, then turn off the heat and let it to cool.

To put the cake together: when it’s completely cold, slice horizontally through the Sponge Cake (1) with a sharp knife. Put the upper part (the “lid”) to one side and try to empty out quite a bit of the lower part – taking care not to break it. Use a brush, dipped in the syrup, to dampen the bottom and sides of the “hole” you have made. Pour in part of the Chantilly cream that you prepared previously (2), just over half (to which you can add fruit in syrup, drained well and cut into small pieces, if you like). Place the “lid” on top of the filling, brush it with syrup as well and then cover it with the remaining Chantilly cream (3). Take the smaller sponge and the part removed from inside the big one, and cut them into small cubes (4); put them in the oven for a few seconds – spaced out well on a steel baking tray, or pan – to toast them slightly (they must not brown). When they’ve cooled, scatter them over the cake (5-6) which will look as though it’s covered in little yellow flowers…. like mimosa!

(*) In order to obtain enough little cubes – “flowers” – to cover the surface of the cake properly, you should make 2: one with the ingredients indicated, and another smaller one with roughly half of the quantities (or you can settle for decorating the cake with a few "flowers", here and there, by cutting up the sponge removed to make space for the cream filling).