Chocolate Mousse

My sister, Pam who is an amazing cook, brought this delicious dessert to me for my birthday.  I honestly thought it was the best thing I had ever eaten.  It is so smooth and chocolaty and yummy.  I had to share the recipe:
Chocolate Mousse
1 1/2 cups mini marshmallows
1/4 cup soft butter
9 oz bittersweet chocolate (minimum 70%cocoa solids) chopped into small pieces
1/4 cup hot water
1 cup heavy cream
1 teaspoon vanilla extract

Put the marshmallows, butter, chocolate and water in a heavy saucepan.  Out the saucepan over gentle heat and cook until melted together, stirring frequently.  Remove from heat.
Whip the cream and add the vanilla.  It should be think.  Fold the cream into the cooling chocolate mixture until it is smooth and cohesive.  Pour into glasses or ramekins and chill.  Serve with whipped cream on top, garnished with shaved chocolate curls.