Black Bottom Peanut Butter Mousse Pie

My husband's birthday was yesterday, and I made this little concoction especially for him. He has a strange obsession with peanut butter, so I knew this would be the best birthday cake --- and I was right. He absolutely loves it.

1 Graham Cracker Pie crust (I took the shortcut, you can make your own)
1 1/3 cups bittersweet or semisweet chocolate chips (about
8 ounces)
2/3 cup plus 1 3/4 cups chilled whipping cream, divided
2 tablespoons light corn syrup
2 teaspoons vanilla extract, divided
6 ounces (1 cup) peanut butter chips
2 tablespoons creamy peanut butter (do not use old-fashioned style or freshly ground)
2 tablespoons sugar

1. Combine chocolate chips, 2/3 cup cream, corn syrup, and 1 teaspoon vanilla in microwave-safe bowl. Microwave on medium heat until chocolate softens, about 3 minutes.
2. Whisk until melted and smooth. Spread chocolate mixture over bottom of crust. Freeze 10 minutes.
3. Microwave 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.
4. Whisk in peanut butter and 1 teaspoon vanilla. Cool to barely lukewarm.
5. 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.
6. Spoon mousse over chocolate layer. Chill at least 1 hour and up to 1 day.