Winter warmup: Sunny days are here again, thanks to dried summer stone fruit
First, prepare the filling: In a small saucepan, combine the water, apricots, Grand Marnier and orange juice. Bring to a boil over medium-high heat, remove from the heat, and leave to soak for 1 hour.
Meanwhile, divide the Sugar Dough in half and, on a lightly floured work surface, roll out one half to a circle about 1/8 inch (3 mm) thick and large enough to line a 10-inch (25-cm) tart pan. Loosely roll up the dough around the rolling pin, unroll onto the pan, and gently press into the bottom and sides. With scissors or a sharp knife, carefully trim the edges, adding the trimmings to the other half of dough. Refrigerate the lined pan.
Roll out the second half of the dough to a 10-inch (25-cm) square; then, using an inverted 9-inch (22.5-cm) round, cut out a circle. Loosely roll up the circle around the pin and unroll onto a lightly floured sheet of waxed paper. Using a 1/2-inch (12-mm) circular cutter or pastry tip, cut out a random pattern of circles, leaving a rim of dough about 1/2 inch (12 mm). Gather up the cutouts and refrigerate or freeze for another use. Refrigerate the circle of dough.
Strain the liquid from the apricots. Transfer the apricots to a bowl and return the liquid to the saucepan. Boil until reduced to 3 tablespoons. Set aside to cool.
In a large skillet, lightly toast the pine nuts over medium heat, stirring constantly and taking care not to burn them. Stir the sugar and a third of the pine nuts into the apricots.
Using the paddle attachment of an electric mixer, or a handheld electric beater, beat the butter until fluffy. Stir in the cooled liquid and orange zest.
Preheat the oven to 375 F (190 C).
To assemble the tart, spread the jam over the bottom pastry. Arrange the apricot mixture evenly on top. Sprinkle with the remaining pine nuts. Top with the butter mixture. Carefully top with the cutout pastry circle.
Bake until golden brown, about 35 minutes. Transfer to a rack. Serve slightly warm or at room temperature, accompanied by vanilla ice cream or whipped cream.