Generally speaking, I am not a big soda drinker. In fact, the only time I ever really want a carbonated beverage is during a sour morning-after hangover. It wasn’t always so. During the endless summers of grade school, I craved orange soda pop and only orange soda pop—no grape, no cola (certainly never water). This light, citrusy, summery tart is an elegant nod to my old obsession. It actually features orange soda as a main ingredient, yet the look and texture suggest something decidedly more upscale. It’s soda-fountain quaint with a whiff of Le Cordon Bleu, and it is delicious.
Place the butter in a large bowl. Set aside.
In a wide bowl, sprinkle the gelatin evenly over the lemon juice (take care that the gelatin does not clump).
In a medium saucepan, stir together the orange juice and soda. Bring the liquid to a boil and cook until it is reduced by half, or 1 cup. Turn the heat to low and whisk to release excess heat.
In a medium bowl, whisk together the lemon and orange zest, eggs, egg yolks, and sugar and pour the mixture into the saucepan. Cook over medium-low heat, whisking constantly, until a candy thermometer reads 180 degrees F, or the curd can easily coats the back of a wooden spoon.
Remove the pan from the heat and add the gelatin mixture. Whisk until the gelatin is completely combined. Pour the liquid through a fine-mesh sieve directly onto the butter. Whisk the mixture furiously until it has increased a bit in volume (the faster you whisk, the more voluminous it will be). Cover the top of the curd with plastic wrap, pressing the plastic directly onto the curd’s surface, and refrigerate for at least 4 hours.
In the bowl of a standing mixer fitted with the paddle attachment, beat the butter, sugar, zest, and salt until light and fluffy. Add the egg, and beat just until incorporated. Scrape down the bowl, add the flour all at once, and beat just until the dough comes together in a ball. Do not overbeat, or your crust will be hard.
Remove the dough from the bowl, shape it into a disk with your hands, wrap it tightly in plastic wrap, and refrigerate it for at least 30 minutes.
Dust a work surface with a sprinkling of flour. Use a rolling pin to roll the dough into a 10-inch circle about ¼ inch thick. (Note: The dough will be sticky. Make sure to turn it over with a bench knife or offset spatula as needed and to keep the work surface floured.)
Ever so gently, guide the dough, without pulling it, into a 9-inch tart pan with a removable bottom and lightly press it into place. Roll the rolling pin over the pan to trim off excess. Place the tart pan in the freezer for 30 minutes.
Line the tart shell with aluminum foil and fill it three-quarters full with pie weights or dried beans.
In the bowl of a standing mixer fitted with the whisk attachment, beat the curd on high for 5 minutes, then spoon it into the tart and level the filling with an offset spatula. Refrigerate the tart for 1 hour to set completely.
Make the Orange Whipped Topping
Pour the cream into a chilled metal bowl and beat it with a chilled whisk for about 1 minute. Sprinkle the sugar and orange cream soda on top and continue whisking vigorously until soft peaks form. (The whipped cream can be made in the bowl of a standing mixer fitted with the whisk attachment, but the hand-whisking method burns more calories. Also, if you prefer, you can substitute Simple Whipped Cream, for the flavored topping.)
To serve, gently push up on the tart bottom to release it from the pan. Top the tart with orange whipped cream.
The tart tastes best if eaten within 24 hours but can be kept, covered, in the refrigerator for up to 2 days.
© 2010 All rights reserved. Published by Abrams Books.