03Microwave peanut butter chips and 3/4 cup cream in large microwave-safe bowl on medium heat at 15-second intervals just until chips soften, stirring often. Whisk in peanut butter and 1 teaspoon vanilla. Cool to barely lukewarm. Beat remaining 1 cup cream and 2 tablespoons sugar in medium bowl until very thick but not yet holding peaks; fold into peanut butter mixture in 3 additions. Spoon mousse over chocolate layer. Chill at least 1 hour and up to 1 day.