Melt the butter and chocolate together and set aside.
Mix the eggs, yolks, lemon zest, and sugar.
Add the lemon curd.
Mix the two preparations together.
Add the sifted flour and don't overmix.
Line the sides of the individual cake rings of 6 cm in diameter and 4.5 cm in height with parchment paper and place on top of a tray with a silpat.
Pour 90g of the batter into the cake rings with a piping bag.
Bake at 190 degrees celsius for about 7 minutes. Time may very depending on your oven and mold. The middle of the cake needs to be soft in order to be runny when it is served.