Hamantaschen

Cut the butter into cubes and refrigerate for at least 30 minutes. In a liquid measuring cup, whisk the cream and egg yolk together. Cover and refrigerate.
In a medium bowl, whisk together the flour and salt.
In a food processor, blitz the sugar until fine. Toss in the cold butter cubes and pulse until the sugar disappears. Add the flour mixture and pulse until the butter pieces are no larger than small peas.
Add the egg mixture and pulse just until incorporated, about 8 times. The dough will be in crumbly pieces.
Empty the dough into a plastic bag and use the outside of the bag to press it just until it holds together. Remove the dough from the plastic bag and place it on a very large sheet of plastic wrap. Using the plastic wrap, knead the dough just a few times, until it becomes one smooth piece, and there are no visible pieces of butter.
Divide the dough in half. Wrap each piece loosely in plastic wrap and press to flatten it into a 4 inch (10 cm) disk. Refrigerate for at least 30 minutes, or until firm enough to roll.

In a spice mill or blender, grind the poppy seeds. If using ground poppy seeds, measure 3/4 cup.
In a small saucepan, heat the milk over low heat until hot. Add the poppy seeds and stir until the milk is absorbed.
Remove the saucepan from the heat and stir in the sugar, honey, lemon zest, and 1 tablespoon of the apricot preserves until incorporated. Cool the filling to room temperature. Reserve and cover the remaining 1 tablespoon apricot preserves.

In a small bowl, whisk together the egg yolk and milk. Strain the mixture into another small bowl, pushing it through with the back of a spoon. (If it doesn't flow smoothly, let it sit at room temperature for a few minutes.)

Remove a disk of dough from the refrigerator. If the dough has been chilled for more than 30 minutes, allow it to sit until it is soft enough to roll, 5 to 10 minutes.
Lightly dust a large piece of plastic wrap with flour. Set the dough on top and lightly flour the top. Cover with another piece of plastic wrap and roll the dough into a 1/8-inch (3-mm) thick oval.
Remove the top piece of plastic wrap and cut out the cookies with the 3-inch (8-cm) cutter. Place each one on a foil disc. Gather up the scraps and knead them together lightly. Shape into a flat patty, wrap in plastic wrap, and refrigerate until firm enough to reroll.
Repeat with the remaining disk of dough.

Brush the outer 1/2 inch (6 mm) of each dough round with a thin coating of egg glaze. Place 2 teaspoons poppy seed filling mounded in the center of the round.
Firmly pinch the dough together at three equally spaced places to form the three-corner-hat effect. Press the foil up against the sides of the dough to conform to the shape, then fold in the excess foil at each corner to secure it. Bend back the top edges of the foil slightly so they don’t rise above the dough.
Line a rimmed baking sheet with parchment paper. Place the hamantaschen about 1 1/2 inches (4 cm) apart on the baking sheet. Refrigerate, covered with plastic wrap, until firm, at least 30 minutes or up to overnight.

Preheat the oven to 350°F (180°C) with a rack set in the middle position.
Bake until the hamantaschen are lightly browned, rotating the baking sheet once during cooking, 15 to 20 minutes. Set the baking sheet on a wire rack. Use the edges of the foil “pans” to lift the hamantaschen to a separate wire rack to cool completely.
When the cookies are cool, brush the poppy seed filling with the remaining 1 tablespoon of apricot preserves. If necessary, stir in a little apricot brandy or hot water to make it more liquid. Remove the hamantaschen from the foil before serving.