Position a rack in the lower third of an oven and preheat to 450ºF.
Grease two 6-oz. ramekins and dust lightly with cocoa powder.
In a medium heatproof bowl, combine the chocolate and butter.
Set the bowl over but not touching simmering water in a saucepan and melt the chocolate and butter, stirring often, until smooth and blended.
(Do not overcook.) Let cool to room temperature.
In a bowl, whisk together the eggs and sugar until completely blended and frothy.
Using a large spatula, gently fold in the chocolate mixture until smooth and blended.
Sift half of the flour over the batter and gently fold together until just blended, then repeat with the remaining flour.
Divide the batter among the prepared ramekins and bake until the tops are just firm when lightly touched, 10 to 12 minutes.
Serve warm with the vanilla ice cream and raspberries.