molten-centered chocolate cake

In response to this entry, Jean-Georges Vongerichten's molten-centered chocolate cake recipe (which appeared in Martha Stewart Living, Nov. 1998, and which we've modified slightly).

1 stick unsalted butter, plus more for molds
2 tsp. all-purpose flour, plus more for molds
4 oz. bittersweet chocolate (we usually use Guittard)
2 large whole eggs
2 large egg yolks
1/2 cup sugar (we use less, 1/4 to 1/3 cup, and we use erythritol)

Preheat oven to 450F
Butter and flour four small baking dishes (we use 6-oz. Pyrex custard cups; you could use something smaller)
Melt butter and chocolate in double boiler
Mix eggs, yolk, and sugar with electric mixer in large bowl
Mix in butter-chocolate mixture, then flour.
Pour batter into baking dishes, place them on a baking sheet, and bake for 6-7 minutes.
For each baking dish, put it onto a potholder, invert a small plate over it, flip things over, wait 10 seconds, and lift the baking dish off.
Top with something pretty: sift powdered sugar over the top, or drizzle with berry puree, or something like that.