Step 1
Preheat oven to 375 degrees F. Adjust a rack to the middle of the oven. Butter six 4-ounce ramekins.

Step 2
Put the chocolate and butter in a metal or glass bowl over barely simmering water. Stir occasionally until melted. Remove from the heat.

Step 3
Place the eggs, sugar, and salt in the bowl of a mixer. Whip at medium-high speed until light and fluffy, about 5 minutes. Reduce speed to low and add the chocolate; mix until combined. Spoon into the prepared ramekins and place on a baking sheet.

Step 4
Bake for about 10 minutes or until the edges are set but the center is underdone. Let cool 3 minutes before serving.