Bake this silky, rich chocolate mousse straight out of the freezer. It couldn’t be easier and you can make a half-batch without compromising the results. For a molten center, stick with the 4-oz. size. For a cooked-through but still meltingly tender crumb, choose the heart-shaped ramekins or any other flat 3-oz. ramekins. Needless to say, they make a killer Valentine’s Day dessert.