Preheat the oven to 450°F. Butter four 4-inch ramekins and sprinkle each with a bit of sugar; place them on a sheet tray.
In a small, heavy saucepan, melt the butter over low heat. Add the chocolate and whisk constantly until the chocolate begins to melt. Remove from heat and continue whisking until the chocolate is completely melted. Let cool slightly.
In a medium bowl, whisk together the eggs and egg yolks with the sugar until light and fluffy. Slowly pour the melted chocolate and butter into the eggs, whisking constantly. (You can use electric beaters or a stand mixer if you prefer).
Pour the mixture into the ramekins and bake for about 8 minutes or until the center is beginning to set. The tops will puff up slightly like souffles but the centers will be deliciously soft and gooey. Cut a small hole in the top of each one and add a scoop of vanilla ice cream or gelato. Serve immediately in the ramekins, on small dessert plates. (Be careful, they are hot!!)
MAKE AHEAD: You can make the batter and fill the ramekins several hours ahead. Cover with plastic wrap and refrigerate until ready to use. Bring to room temperature before baking.