Heat oven to 325° F. Lightly coat a 12-cup muffin tin with vegetable cooking spray.
Melt the chocolate and butter in a large bowl over a saucepan of simmering water. Remove from heat.
In another large bowl, beat the eggs and sugar at medium-high speed until light and fluffy. Add the flour, baking powder, salt, and melted chocolate. Mix with a spoon until well blended.
Divide the batter evenly into 8 muffin tins and bake until the cakes have just cooked through, about 15 minutes.
The cakes will still look a bit moist on top. Remove from the oven and let cool 5 minutes. Serve warm with the caramel sauce and ice cream.