La Deliziosa (Hazelnut Cream Sandwich Cookies)

Make the filling: Bring half & half and lemon zest to a simmer in a 2-qt. saucepan over medium heat. Whisk sugar, cornstarch, and yolks in a bowl until fluffy. Discard lemon zest and using a ladle, slowly whisk about 1⁄2 cup half & half into egg mixture until incorporated. Return mixture to pan; cook, whisking constantly, until very thick, about 6 minutes. Transfer pastry cream to a bowl. Place a piece of plastic wrap directly onto the surface of cream to prevent a skin from forming; chill 1 hour.

Using an electric hand mixer, beat butter in a bowl until fluffy. Add the chilled pastry cream and the hazelnut paste; mix until combined. Cover with plastic wrap; chill until firm, about 1 hour.

Make the cookies: Pulse the flour, sugar, baking powder, and salt in a food processor. Add butter, pulse until pea-size crumbles form. Add eggs and zest; pulse until dough forms. Add 1-2 tbsp. cold water, if necessary, until dough holds together, but is not wet. Form dough into 2 disks; wrap in plastic wrap and chill 1 hour.

Heat oven to 350°. On a lightly floured surface and using a rolling pin, roll 1 disk dough into a 10” circle, about 1⁄4” thick. Using a 3” round cutter, cut out cookies and transfer to parchment paper-lined baking sheets. Roll and reuse scraps. Bake rotating cookies once, until just golden, about 20 minutes. Let cookies cool completely.

Assemble the cookies: Spread about 1 1⁄2 tbsp. filling evenly on half the cookies, leaving no border; top with remaining cookies and lightly press together. Roll sides of cookies in remaining chopped hazelnuts. Dust cookies with confectioners’ sugar; chill until filling is firm, at least 1 hour.