Heat the oven to 400°. In a small bowl, stir together sugar and cinnamon. In another bowl, make an egg wash by whisking the egg and milk.
Sprinkle each pear half with the cinnamon sugar on both sides, then place the pears, cored side down, on a parchment-lined baking sheet, spacing them evenly.
Roll out a sheet of puff pastry to remove its score marks. Cut the sheet into 4 rectangles. Wrap each pear with a piece of pastry and trim away the excess. Use the scraps to make a leaf shape for each pear. Attach the pieces with the egg wash.
Bake until the pastry is puffed and golden brown, about 20 minutes. Let the pears cool 10 minutes before flipping them over and serving with a dollop of whipped cream or ice cream.