Make the crust: In a food processor, pulse the flour and salt to combine. Add the butter and pulse until the mixture resembles coarse crumbs. Gradually add 3 tablespoons of ice water, pulsing until the dough comes together, adding the last tablespoon if needed. Shape into a disk, wrap in plastic, and chill for 30 minutes. Preheat the oven to 375°F (190°C). Roll out the chilled dough on a floured surface into a 12-inch circle. Transfer to a 9-inch pie plate, trim the edges, and crimp decoratively. Prick the bottom with a fork, line with parchment paper, and fill with pie weights. Bake for 20 minutes, remove the weights and parchment, and bake for another 10-15 minutes until golden. Let cool completely.

Make the filling: In a medium saucepan, whisk together milk, cream, sugar, cornstarch, and salt. Cook over medium heat, whisking constantly, until the mixture thickens and begins to bubble, about 5 minutes. In a separate bowl, whisk the egg yolks. Gradually whisk 1 cup of the hot milk mixture into the yolks to temper them, then whisk the yolk mixture back into the saucepan. Cook, whisking constantly, until thickened, about 2 more minutes. Remove from heat, and stir in butter and vanilla until smooth. Pour the filling into the cooled crust, smooth the top, press plastic wrap directly onto the surface, and refrigerate for at least 4 hours or overnight until set.

Make the topping: Beat the heavy cream, powdered sugar, and vanilla with an electric mixer on medium-high speed until stiff peaks form. Spread or pipe the whipped cream over the pie before serving.