Viennese Chocolate Souffle Recipe

Beat egg yolks and sugar until very thick in the top of a double boiler.
Add the flour gradually, beating until smooth.
Gradually add the milk, continuing to beat until blended.
Place over rapidly boiling water.
Cook and stir 5 minutes, or until thickened.
Remove from water; add the chocolate and stir until blended.
Mix in the extract.
Set on wire rack; allow to stand until mixture cools to lukewarm.
Meanwhile, butter a 2-quart souffle dish (straight-sided casserole).
Sprinkle lightly with sugar to coat bottom and sides.
Fold a length of aluminum foil and tie around souffle dish to give additional height.
Beat the egg whites until stiff, not dry, peaks are formed and immediately fold with the chocolate mixture.
Gently turn into the collared souffle dish and immediately set in oven on rack (placed so top of product will be about at center of oven).
Bake at 375°F 45 to 50 minutes.
Remove from oven and carefully remove foil collar.