Prepare ramekins with preferred non-stick method. Preheat oven to 450F.
Using a double boiler heat chocolate and butter until melted. Set chocolate sauce aside to cool slightly.
In a large bowl, whole eggs, egg yolks, and sugar. With a hand mixer beat until egg mixture is fluffy and a pale yellow color, about 2-3 minutes.
Add coffee, vanilla, salt, and chocolate sauce. Fold until mostly combined.
Fold flour into the mixture until just incorporated . Do not overmix.
Divide batter evenly into prepared ramekins.
Bake at 450F for 10-12 minutes. Smaller ramekins will need less time.
Let cakes cool for about 1 minute, and invert onto plate for serving.
Garnish with powdered sugar, ice cream and/or berries.