Preheat the oven to 180°C.
Melt the butter and half of chocolate over a bain marie, stirring occasionally.
Mix well in a separate bowl both types of flour, sugar and the eggs, then add the melted chocolate, incorporate the remaining pieces of chocolate, mix it all together to amalgamate well.
Line a rectangular pan of about 25 × 30 cm with wet and squeezed parchment paper.
Bake for 25-35 minutes at 180°C.
When cooked, allow the cake to cool in the pan and then cut it into squares.
Serve with whipped cream, vanilla ice-cream or simply soak in a glass of milk.
Enjoy with love!