Break the chocolate into pieces and melt with the butter in a saucepan over low heat and allow to cool. Place the baking molds in the hollows of a mini muffin tin or put 2 molds inside each other and spread them on a baking sheet. Preheat the oven to 175 ° C (top and bottom heat, circulating air: 150 ° C, gas: according to the manufacturer`s instructions).
Mix the flour, baking powder and cocoa together. Mix the eggs, sugar and a pinch of salt with the whisk of the hand mixer for 5 minutes until creamy. First stir in the liquid chocolate, then the flour mixture and then the milk. Pour the batter into a disposable piping bag or use 2 teaspoons and pour into the molds.
Bake in the hot oven for 6 - 8 minutes. Take out of the oven and immediately press the toffifee lightly into the batter. If the dough is still a little runny inside, it doesn`t matter, it becomes firmer when it cools down. Let the muffins cool before serving.