On a lightly floured surface, roll All-Butter Piecrust into a 12-inch circle (about ⅛ inch thick). Gently transfer to a 9-inch pie plate, and trim excess to ½ inch beyond edge of plate. Fold excess under, and crimp as desired. Prick bottom of dough all over with a fork, and freeze until firm, about 15 minutes.

Preheat oven to 425°F (220°C).

Top dough with a piece of parchment paper, letting ends extend over edges of plate. Add pie weights.

Bake until edges are golden brown, about 15 minutes. Carefully remove parchment and weights, and bake until bottom of crust is dry and golden, 5 to 7 minutes more. Let cool completely.

In a medium bowl, whisk together egg yolks, cornstarch, and salt.

In a medium saucepan, whisk together puréed peaches, granulated sugar, and lemon juice. Whisk in egg yolk mixture. Cook over medium-low heat, whisking constantly, until thickened and an instant-read thermometer registers at least 175°F (80°C), 6 to 8 minutes.

Remove from heat, and whisk in butter until melted and well combined. Pour filling into prepared crust. Cover with plastic wrap, pressing wrap directly onto surface of filling to prevent a skin from forming. Refrigerate until thick and cold, at least 2 hours, or up to overnight.

Just before serving, in the bowl of a stand mixer fitted with the whisk attachment, beat cold cream, confectioners’ sugar, and vanilla at medium-high speed until medium-stiff peaks form. Spread onto pie; garnish with peach slices, if desired. Refrigerate in an airtight container for up to 3 days.