1 (9-inch) pie dough round
1 3/4 cup pure maple syrup
2/3 cup heavy cream
1/4 teaspoon salt
5 tablespoons unsalted butter
2 tablespoons cornstarch
3 large eggs plus 2 large egg yolks
2 teaspoons cider vinegar
1. Adjust oven rack to middle position and heat oven to 375 degrees. Grease 9-inch pie plate. Roll dough into 12-inch circle on lightly floured counter. Loosely roll dough around rolling pin and gently unroll it onto prepared pie plate, letting excess dough hang over edge. Ease dough into plate by gently lifting edge of dough with your hand while pressing into plate bottom with your other hand.
2. Trim overhang to 1/2 inch beyond lip of pie plate. Tuck overhang under itself; folded edge should be flush with edge of pie plate. Crimp dough evenly around edge of pie plate using your fingers. Wrap dough-lined pie plate loosely in plastic and freeze until dough is firm, about 15 minutes.
3. Line chilled pie shell with parchment paper or double layer of aluminum foil, covering edges to prevent burning, and fill with pie weights. Bake until edges are light golden brown, 18 to 25 minutes, rotating pie plate halfway through baking. Remove parchment and weights and continue to bake until center begins to look opaque and slightly drier, 3 to 6 minutes. Remove from oven and let cool for at least 30 minutes. (Baked, cooled crust can be wrapped in plastic and stored at room temperature for up to 24 hours.)
4. Reduce oven temperature to 350 degrees. Bring maple syrup, cream, and salt to boil in a medium saucepan. Add butter and whisk until melted. Reduce heat to medium-low and whisk in cornstarch. Bring to simmer and cook for 1 minutes, whisking frequently. Transfer to large bowl and let cool at least 30 minutes. Whisk in eggs and yolks and vinegar until smooth. (Cooled filling can be refrigerated for up to 24 hours. Whisk to recombine and proceed to step 5, increasing baking time to 55 to 65 minutes.)
5. Place cooled crust on rimmed baking sheet, and pour filling into crust. Bake until just set, 35 to 45 minutes. Let pie cool completely on wire rack, about 2 hours. Transfer to refrigerator and chill until fully set, at least 2 hours or up to 24 hours. Serve cold or at room temperature.
1 cup pasteurized heavy cream, room temperature
2 tablespoons buttermilk, room temperature
Combine cream and buttermilk in 1-pint jar. Cover jar with triple layer of cheesecloth and secure with rubber band. Let sit in warm place (about 75 degrees) until thickened but still pourable, 12 to 24 hours. Stir to recombine. Serve. (Crème fraîche can be refrigerated for up to 1 month.)