1. Place a rack in the middle of the oven and preheat to 350 F.
2. Grease or spray a 9-inch cake pan or 12 cup muffin tin with vegetable or canola oil. Wipe out the excess oil with a paper towel. Set aside.
3. Grate the chocolate or chop it into small shards with a chef’s knife or a serrated knife. Place the chocolate in the top of a double boiler or a large bowl set over a saucepan of simmering water over low heat. Melt the chocolate slowly, stirring occasionally.
4. In a medium bowl, gently whisk together the eggs, egg yolks, sugar, and flour. Mix until all the ingredients are well incorporated.