Heat the oven to 375°F (190°C) and line a baking sheet with parchment. Keeping the baking sheet ready before you begin makes it easier to transfer the delicate pastry flowers without stretching them.

Whisk the pumpkin purée, brown sugar, egg, vanilla, cinnamon, ginger, nutmeg, and salt in a bowl until smooth. The mixture should be evenly blended, with no visible streaks of egg or clumps of brown sugar.

Unroll the chilled pie crusts and use a 3- to 3 1/2-inch flower-shaped cookie cutter to cut 24 pastry flowers. If the dough becomes soft while cutting, place the shapes in the refrigerator for 10 minutes before assembling.

Place 12 pastry flowers on the parchment-lined baking sheet. Spoon approximately 1 tablespoon of pumpkin filling into the center of each flower, keeping the filling away from the petals so the decorative shape remains visible.

Lay a second pastry flower over each filled base. Press the center and outer edges together gently, then use a fork to seal the inner edge if needed; avoid pressing so firmly that the petals lose their shape.

Cut one or two small slits in the center of each top crust to let steam escape. Brush the pastry with the egg wash made from one beaten egg and 1 tablespoon of water, then sprinkle with granulated sugar if desired.

Chill the assembled pies for 15–20 minutes. This firms the pastry and helps the flowers hold their shape as they enter the hot oven.

Bake for 20–25 minutes, until the crust is golden brown and the pumpkin filling is set. Cool the pies on the baking sheet for at least 10 minutes before serving, since the filling remains hot and delicate immediately after baking.