Add the 4 eggs to the flour mixture. Start bringing the dough together with a wooden spoon, then switch to your hands, working it until it forms a ball. This dough is quite sticky; if it's too difficult to handle, add a small amount of flour, no more than 1 or 2 tablespoons, to avoid diluting the sweetness or making the dough tough. Knead it briefly, just 2 or 3 times, on a cool surface. Wrap the dough ball in cling film and chill in the fridge for at least 1 hour, or ideally overnight.
When ready to bake, preheat your oven to 180°C / 350°F. Grease each of your tartlet cases thoroughly; a piece of buttered greaseproof paper works well. On a floured surface, roll out the pastry until it's about 2mm to 3mm thick. Use your cutter to cut out circles, re-rolling scraps as needed.
Carefully but firmly press the pastry discs into their metal cases, ensuring they sit evenly and come slightly over the top edge. Avoid pressing too much, which can make the pastry too thin. Prick the base of each pastry case all over with a fork.
