We made this for a New Year’s party in grad school. It was a hit.
(From Joanne Drexler, who modified a Nigella Lawson recipe from the Today Show.)
1 1/2 cups mini marshmallows
4 Tbsp (1/2 stick) soft butter
9 oz best-quality bitter-sweet (~60%) chocolate, chopped into small pieces
1/4 cup hot water from a recently boiled kettle
1 cup heavy cream
1 tsp vanilla extract
Combine marshmallows, butter and chocolate with water in a heavy-bottomed saucepan and melt over a gentle heat, stirring every now and again. Remove from heat.
Meanwhile, whip the cream with vanilla until thick. Fold into the cooling chocolate mixture, until you have a smooth, cohesive texture.
Pour/scrape into 4–6 serving dishes, glasses, or cups. Chill until ready to eat.