Fill double boiler pot about half-way and bring to a boil.
Break the chocolate into smaller squares. Cut up the butter into small cubes or slices to help it melt faster. Put the chocolate and butter into the top of the double boiler (we use a pyrex bowl on top of a pot). Using a whisk, stir the chocolate and butter together until smooth.
In a medium bowl, beat the eggs, egg yolks, sugar, salt, and flour together, normally 2 and a half minutes on a medium/high setting. Or until the mixture is thickened and a little pale.
When the chocolate/butter is smooth, fold the chocolate into the egg mixture. Spoon the batter into the ramekins. If you use 4 oz ramekins, they will be mostly full (the cakes do rise a little bit, but not too much).
Bake for 8-10 minutes, or until the sides of the cakes are firm, but the centers remain soft. Remove from the oven and let sit for 1-2 minutes. Then cover the cake with an inverted plate and flip over (we use tongs to help this process, but you could just use an oven mitt). After about 10-15 seconds, you should be able to remove the ramekins with a slight shake. If they don't come out, flip back over and use a think knife or toothpick to run along the edges of the cake and try again.
Lightly dust with powdered sugar. Place fruit on plate and whipped cream if you choose. Add a tall glass of milk for the finishing touch.
