Hot Chocolate Cake

Ingredients
8 T. unsalted butter (1 stick) plus extra for coating
10 ounces bittersweet or semisweet chocolate, coarsely chopped
3 T. flour, plus extra for dusting
1/2 cup sugar, plus extra for dusting
4 large eggs
1 large egg yolk
1 tsp. vanilla
1/4 tsp. salt
1 cup mini-marshmallows
2 T. cocoa powder, optional

Directions
Preheat oven to 375. Generously butter, flour and sugar eight or nine 6-ounce oven-proof ramekins. (You can also bake this in a 9 or 10-inch pie plate; increase baking time 22-25 minutes or if you prefer a gooey center 17-20 minutes.) Place butter and chocolate in double boiler over simmering water and melt until smooth, cool. Beat the eggs, yolk, sugar, vanilla and salt on high speed until volume doubles and the mixture becomes foamy, about 5 minutes. Stir in the 3 T. flour, then gradually add the melted chocolate to the egg mixture beating on low until fully incorporated. Fill the ramekins two-thirds full and bake until the cakes puff and begin to crack but the centers are still a bit runny, 13-17 minutes. Remove from oven and sprinkle with marshmallows and return to oven for 2 to 4 minutes, until the marshmallow tops begin to brown. Remove from oven and let cool about 5 minutes. Sift the cocoa on top of marshmallows. Note: if you fill the cups too full it is hard to get the marshmallows to stay on, because these cakes puff up when they cook and sink a little when they cool.