Place vodka in small bowl. Stir in 1/2 cup of the cereal, let stand 15 minutes.
Place cream in another small bowl, stir in remaining 1/2 cup cereal. Refrigerate 15 minutes, stirring once.
In 1-quart saucepan, combine sugar and water. Heat to boiling, stir until sugar is dissolves. Remove from heat, set aside to cool.
Stir vodka and cream mixtures. Strain mixtures into 2-cup glass measuring cup to remove cereal, discard cereal. Pour vodka-cream mixture into beverage shaker or quart-size jar with lid. Add lemon and lime juices, egg whites and sugar mixture. Shake drink like crazy. Add ice cubes to shaker, shake again like crazy.
Strain drink into 4 chilled martini glasses. Hit the foamy top with a dash of bitters.