Lemon Butter Cookies
- In a bowl, combine the flour and baking powder. Set aside.
- In another bowl, cream the butter and sugar with an electric mixer. Add the egg yolk and lemon zest, beating until smooth. At low speed, or with a wooden spoon, stir in the dry ingredients until smooth. Shape the dough into a disc and cover with plastic wrap. Refrigerate for 30 minutes.
- With the rack in the middle position, preheat the oven to 350°F (180°C). Line two baking sheets with parchment paper or silicone mats.
- On a lightly floured surface, roll out the dough into a 1/8-inch (3 mm) thick sheet. With a 2 ½-inch (6 cm) round cookie cutter, cut out 24 cookies. Reuse the scraps. Place on the prepared baking sheets and refrigerate for 15 minutes.
- Bake, one sheet at a time, for 10 to 12 minutes or until the cookies are lightly golden brown. Let cool completely.
- In a saucepan off the heat, combine ½ cup (105 g) of the sugar and the cornstarch. Add the eggs and whisk thoroughly. Add the strawberry purée and lemon juice. Bring to a boil over medium heat, stirring constantly, scraping the sides and bottom of the saucepan until the mixture thickens. Let simmer for 1 minute. Transfer to a bowl. Cover and refrigerate for about 3 hours or until completely chilled.
- In another bowl, whip the cream with the remaining sugar (¼ cup/55 g) until stiff peaks form. With a whisk, gently fold the whipped cream into the strawberry mixture.
- Spoon the strawberry cream into a pastry bag fitted with a large star tip, and generously pipe onto half of the cookies. Top with the remaining cookies and press lightly. Freeze for about 4 hours.
- Serve or individually cover the parfait sandwiches in plastic wrap.
To obtain 1 cup (250 ml) of strawberry purée, process about 2 cups (280 g) of fresh strawberries until smooth and strain through a sieve.