Makes: two 1-quart soufflé molds
Preheat oven to 375 degrees. Butter the bottom and sides of 2 1-quart soufflé molds. Sprinkle with sugar; shake out excess. Place dishes on a baking sheet and set side.
Melt butter over low heat in a saucepan. Stir in the flour and cornstarch; stir until smooth. Pour in the milk and sugar. Whisk over medium heat until thickened. Remove from heat. Transfer to a large mixing bowl. Mix in the egg yolks, sugar and vanilla. Blend in the Grand Marnier.
In an electric mixer, beat the egg whites with the cream of tartar to until soft peaks form when beater is lifted. Add sugar gradually while beating constantly until the egg whites are firm. Fold the egg whites into the Grand Marnier mixture. Divide the soufflé mixture between the two prepared molds. Bake for 30 to 35 minutes. Sprinkle with powdered sugar before serving. Serve with Macademia nut sauce.
MACADEMIA NUT SAUCE
Combine all ingredients in a blender. Blend at high speed until the sauce is smooth and medium thick. Transfer to a bowl. Cover with plastic wrap. Serve with soufflés.