Lemon Custard Tart

For the Tart Shell and Cookies

• 2 cups all-purpose flour, plus more for dusting
• 8 tbsp. almond flour
• ¹⁄₄ tsp. kosher salt
• 1 cup plus 2 tbsp. confectioners' sugar
• 12 tbsp. unsalted butter, softened
• 1 egg

For the Filling and Garnish

• 1 lemon, thinly sliced, seeds discarded
• 2 ²⁄₃ cups sugar
• ¹⁄₄ cup grated lemon zest plus 1 1/2 cups juice
• 8 egg yolks, plus 6 whole eggs
• 8 tbsp. unsalted butter, cubed and chilled
• 1 cup heavy cream
• 1 oz. white chocolate, melted and cooled

Instructions

1. Make the tart shell and cookie dough: Whisk flours and salt in a bowl; set aside. Using an electric hand mixer, beat sugar and butter in another bowl until fluffy, 2–3 minutes. Add egg; mix to combine. With the motor running, slowly add dry ingredients until a soft dough forms. Flatten dough into a disk; cover with plastic wrap and chill 1 hour.
2. Heat oven to 325°. On a lightly floured surface, roll dough until ¹⁄₆" thick. Trim dough into a 15" circle. Press dough into bottom and 1 ³⁄₄" up the sides of a 9" cake pan with a removable bottom; trim and gather edges of dough, and set scraps aside. Using a fork, prick the dough in the pan all over. Line dough with parchment paper and fill with pie weights or dried beans; bake until golden and cooked through, about 1 hour, and let cool. Meanwhile, on a lightly floured surface, roll dough scraps ¹⁄₆" thick. Using cookie cutters, cut out 20–25 cookies and place on a parchment paper-lined baking sheet; bake until golden, 10–12 minutes.
3. Make the filling and garnish: Place lemon in a 2-qt. saucepan filled with water; boil. Strain lemon; set aside. Add 1 ¹⁄₃ cups sugar and ¹⁄₂ cup water to pan and bring to a simmer over medium; cook until sugar is dissolved and stir in lemon. Cook until lemon rind is softened and translucent, about 10 minutes; let candied lemon cool in syrup.
4. Whisk remaining sugar, the lemon zest, egg yolks, and eggs in a 4-qt. saucepan until smooth. Whisk in lemon juice; cook, stirring constantly, over medium until thickened, 10–12 minutes. Remove from heat; whisk in cold butter 1 piece at a time until incorporated. Strain curd through a fine-mesh sieve into a bowl; press plastic wrap onto surface of curd and chill.
5. Transfer 1 ¹⁄₂ cups curd to another bowl; set aside. Whip cream in a separate bowl into stiff peaks; fold cream into larger amount of curd and spread evenly into tart shell; chill until set, about 1 hour. Spread reserved lemon curd over lemon cream and top with candied lemon slices; chill 1 hour. Remove tart from pan and transfer to a cake stand or platter. Use melted white chocolate to glue cookies to outer crust of tart.