Preheat oven to 350F.
Place pie crust in 9” pie plate and crimp edges as desired. Chill until ready to fill.
Whisk together butter and peanut butter. If the peanut butter is too stiff to whisk, microwave it for about 20-30 seconds.
Whisk in eggs, sugar, cornmeal, flour, vinegar, and vanilla. Pour into prepared pie shell.
Bake for 35-45 minutes, until crust is browned and top of pie is browned. It will still jiggly slightly in the middle. Mine took 40 minutes. Cool completely before cutting.
Serve with whipped cream or ice cream, or chocolate sauce.