Freeze the filling until it has the consistency of slurry, about 45 minutes. This will make it easier to fill the pies. 

Meanwhile, on a lightly floured work surface using a lightly floured rolling pin, roll out one disk of dough to a ¼-inch (6 mm) thickness. 

Using an upside-down 5-to 6-inch (12 to 15 cm) bowl and a pizza cutter, cut out as many rounds of dough as you can. (Alternatively, use the pizza cutter to cut out 5-to 6-inch/12 to 15 cm squares.) Repeat with the remaining disk of dough. You should have 12 to 18 rounds of dough. Gather the scraps together and pat them into a disk. Wrap in plastic wrap and refrigerate. You can use these scraps to make more rounds (or squares) if needed. 

In a small bowl, whisk together the egg yolk with the cream to make an egg wash. 

Line a baking sheet with a silicone baking mat or parchment paper. 

Hold one round of dough in the palm of one hand and use the warmth of your fingers on the other hand to gently press the dough while turning it counterclockwise, moving from the center of the dough to the edges. This will thin out the dough slightly and make it more pliable. Make one complete rotation, then lay the round on a flat surface. Repeat with 5 more rounds of the dough. 

Place 1 tablespoon of the filling in the center of each thinned dough round. Use a pastry brush to brush the edges of the dough with the egg wash, then gently fold the rounds in half to create half-moons. Use a fork or the handle of a spoon dipped in flour to seal the edges. Use a sharp knife to cut a few slits in the top of each hand pie (this allows steam to escape during baking). Transfer the hand pies to the prepared baking sheet (there doesn't need to be a lot of space between them, so try to fit as many as you can on the same pan). Brush the tops with the egg wash. Repeat with the remaining dough rounds and filling. If you have extra filling, roll out the reserved dough scraps, cut out more rounds, and fill them. 

Freeze for 15 minutes. (At this point, the pies can be wrapped well and frozen for up to 1 month, to be thawed and baked whenever you like.) 

Preheat the oven to 425°F (220°C). 

Bake the hand pies until the tops are a deep golden brown and the filling is bubbling out of the slits, about 25 minutes. Serve as an appetizer on a platter; this is finger food, so there's no need for a plate or forks and knives.