Begin by creaming together unsalted butter and white sugar until fluffy, about 3-4 minutes. Stir in the egg and vanilla until well combined. Gradually add flour, baking powder, and salt until a dough forms. Chill in the refrigerator for 1 hour.

Preheat your oven to 375°F (190°C) and line baking sheets with parchment paper. Have your rolling pin and cookie cutter ready.

Once chilled, roll out the dough to about 1/4 inch thick on a floured surface. Cut out circles with a cookie cutter.

Place a drop of apricot preserves in the center of each circle. Brush the edges with water, fold over to create a half-moon shape, and press to seal.

Arrange cookies on baking sheets and bake for approximately 12-15 minutes, or until golden brown on edges.

Let cool on sheets for about 5 minutes, then dust with confectioners' sugar while warm and transfer to a wire rack.