In a large bowl mix flour and sugar. Cut in the butter until it resembles coarse crumbs. Add the milk and mix gently until it can be shaped into a ball. Shape dough into a round ball and flatten, wrap in plastic, and refrigerate 1 hour, or until firm.
Preheat the oven to 400 degrees F.
In a bowl, combine sugar, flour, and lemon zest. Add berries and roll them in mixture until coated.
Remove dough from the refrigerator and roll out until 1/4-inch thick and roughly 12 inches round. Place on baking sheet.
Mound berries in center of dough, leaving 1 1/2 inches uncovered around the edge. Gently fold the dough up to meet the berries, and drizzle with melted butter.
Mix egg and milk. Brush dough with mixture.
Bake approximately 35 to 40 minutes, or until crust is golden brown.
Let cool and dust with powdered sugar.
Serve warm or at room temperature.
Recipe courtesy of Nathan Strausser