Preheat the oven to 425° F. Prepare the pie crust, line the pie plate with your crust, and chill thoroughly. Dock the base of the crust well with a fork (this means just poking a few holes in it to prevent bubbling), place parchment inside, and line with pie weights. Par bake until lightly golden brown, 15 to 20 minutes. (For more information on par baking: https://food52.com/blog/10858-everything-you-need-to-know-about-par-baking). Take the pie out of the oven and let it cool completely. Reduce oven temperature to 375° F.
In a medium bowl, whisk together the brown sugar, cornmeal, maple syrup, eggs, buttermilk, melted butter, and vanilla to combine.
Pour the custard into the prepared, par baked pie crust. Bake until the custard is set around the edge of the crust, but slightly jiggly in the center , 25-30 min. Remove from the oven and cool completely before slicing and serving.
In a medium bowl, whisk the mascarpone and sugar to combine. Serve each slice with a dollop of mascarpone and a drizzle of maple syrup.
I always carry three kinds of hot sauce in my purse. I have a soft spot for making people their favorite dessert, especially if it's pie. My first cookbook, The Fearless Baker, is out on October 24, 2017.