In a large mixing bowl, combine all-purpose flour and salt. Cut in cold unsalted butter and butter-flavored shortening until coarse crumbs form. Gradually stir in cold water, knead gently, shape into a disk, wrap in plastic, and refrigerate for at least 30 minutes.

In a medium saucepan over low heat, combine frozen sliced peaches, granulated sugar, and light brown sugar. Cook for 10 minutes, mashing gently. Stir in unsalted butter, fresh lemon juice, and cornstarch. Cook for an additional 2-3 minutes, then cool completely.

Whisk together powdered sugar and milk in a small bowl until smooth. Stir in vanilla extract. Set the glaze aside.

Roll out dough to 1/8-inch thick. Cut out circles about 4-5 inches in diameter. Place a spoonful of cooled peach filling in the center and fold over the dough, crimping edges. Repeat until all dough and filling are used.

Heat vegetable oil in a skillet to 350°F. Fry the assembled pies, cooking for 3-4 minutes on each side until golden brown. Drain on a cooling rack.

Once cool enough, brush the warm pies with the vanilla glaze. Allow the glaze to set before serving.