To make the cake: beat the egg yolks, ¼ cup of the sugar, and the lemon zest at high speed in a stand mixer with the whisk attachment, or with a handheld electric mixer, until pale yellow and thick, about 5 minutes.

In a bowl using clean beaters, beat the egg whites with a pinch of salt, beginning at medium-low speed until the whites are frothy, then increasing to medium speed until they are very thick. Slowly add the remaining ¼ cup of sugar, then beat at medium-high speed until the whites form firm, but not dry, peaks that hold their shape when the beater is lifted.

Use a large spatula to gently fold the egg yolks into the whites until mostly combined but still a little streaky. Sift the cake flour over the batter, gently folding, until the flour is evenly incorporated, taking care not to deflate the batter.

Preheat the oven to 350°F (177°C) with rack in the upper and lower thirds of the oven. Line two baking sheets with parchment paper or silicone baking mats.

Scoop the batter into a piping bag fitted with 5/8-inch round tip (Ateco#808). Pipe out 2-inch rounds, forming sixteen rounds on each sheet. Bake just until the tops begin to lightly color, about 12 minutes, rotating the pans halfway through.

Let the cakes cool completely. When they are cool, slide a small offset spatula under the cakes to loosen them, turning them bottom side up and arranging them in matching pairs.

To make the glaze: whisk together the confectioners’ sugar, corn syrup, hot water, and vanilla in a heatproof bowl. Place the bowl over a pan of simmering water so that the bowl is over, but not touching, the water. Stir the glaze just until it is smooth and warm, about 1 minute. Remove the bowl from the pan and set it aside.

To make the pastry cream: Bring the half-and-half and lemon peel to a simmer in a small saucepan.

Meanwhile, in a 2 to 3-quart heavy, nonreactive saucepan, whisk the egg yolks and sugar until they are completely smooth and slightly thickened. Whisk in the cornstarch until it is completely incorporated.

Use a fork to carefully remove and discard the lemon peel from the half-and-half. Add the half-and-half to the egg mixture in a slow stream while whisking constantly. Return the mixture to medium heat and cook, whisking constantly, until the pastry cream boils. Continue to whisk as you boil the mixture for about 30 seconds to make a very thick cream.

Transfer the pastry cream to a bowl. To prevent a skin from forming, press a piece of plastic wrap directly onto the surface. Refrigerate until cold, about 4 hours.

To fill the cookies: spoon a heaping tablespoon of cream evenly over half of the rounds, then sandwich them with their matching tops. Use a small offset spatula to smooth the pastry cream around the edges. Place the filled sospiri on a wire rack set over a rimmed baking sheet.

Check the glaze: if it is cool and stiff, warm it over the simmering water, stirring, until it is thick and pourable. Pour the glaze over the sospiri. To decorate them as they do in Italian pastry shops, sprinkle the sospiti with diavoletti or place a candied cherry on top.

Place each sospiri into a paper cupcake liner, then pack them in a single layer in an airtight container. Cover and refrigerate for 24-48 hour, or up to 4 days.

Reprinted with permission from Southern Italian Desserts: Rediscovering the Sweet Traditions of Calabria, Campania, Basilicata, Puglia, and Sicily copyright © 2013 by Rosetta Costantino with Jennie Schacht. Photography copyright © 2013 by Sara Remington. Published by Ten Speed Press, an imprint of Penguin Random House, LLC.