Wienerbrød

Pound the remaining cold butter between two sheets of parchment into a 7-inch square, then roll the chilled dough into a 12-inch square, set the butter block in the center on the diagonal, and fold the corners over to enclose it completely.

Roll the dough into a long rectangle and fold it in thirds like a letter, then wrap and refrigerate for 30 minutes; repeat this roll-and-fold two more times, chilling between each turn to keep the butter cold and the layers distinct.

Roll the laminated dough to 1/4-inch thick, cut into 4-inch squares, spoon a tablespoon of vanilla pastry cream into the center of each, and fold the corners toward the middle, pressing gently to seal.

Arrange the pastries on parchment-lined baking sheets, cover loosely, and proof at room temperature for 45 minutes until puffy, then brush with beaten egg.

Bake at 400°F for 16 to 18 minutes until deeply golden and flaky, then cool for 10 minutes and drizzle with the powdered sugar glaze before serving.