Prepare soufflé dishes by wrapping a 3-inch-high piece of plastic acetate around tops of each of 7 (5-oz.) straight-sided glasses to form a "collar." Set aside.
Whip cream to medium peaks. Refrigerate until ready to use.
Whisk whole eggs, egg yolks and sugar in metal mixing bowl until combined. Place bowl over simmering water bath. Whisk continuously until mixture reaches 165°F. Pour into electric mixer fitted with wire whip attachment. Whip on medium-high speed to ribbon stage. Continue whipping on low speed 1 min. Mix in mint extract.
Fold in whipped cream in three additions. Fold in OREO Pieces. Portion 4-1/4 oz. mixture into each prepared dish, smoothing tops. Freeze at least 2 hours. When ready to serve, carefully remove plastic collar from dishes.