To prepare a delicious peach cobbler, start by preheating the oven to 180 degrees Celsius. Next, spread a sheet of shortcrust pastry on a tart pan. In a separate bowl, mix 1/2 cup sugar, 1 tablespoon flour, and 1 teaspoon ground cinnamon. Place the slices of 4 peeled peaches on the dough and sprinkle the sugar, flour and cinnamon mixture over the peaches. Fold the edges of the dough over the filling and brush with beaten egg. Bake the pie for about 30-35 minutes, until the crust is golden brown and the peaches are tender. If you wish, you can sprinkle icing sugar over the cake before serving. Enjoy this sweet and juicy peach pie!