1. Butter and sugar molds.
2. In a mixing bowl, slowly melt the butter and chocolate over a bain marie of hot water.
3. Make sure that the eggs and egg yolks are at room temperature and mix the two together.
4. Using the whisk attachment, slowly mix the powdered sugar and egg mixture into the melted chocolate until smooth.
5. Add the sifted flour all at once and mix until homogenous.
6. Fill the pre-buttered and sugared molds to three-quarters full with the chocolate mixture.
7. Refrigerate and when ready to serve bake at 375°F for about 10-15 minutes.

Chefs' Note
Do not over-bake the cakes, otherwise you will not get the soft center effect.