Place the sliced (or peeled) peaches in a large bowl.
Thoroughly blend brown sugar, white sugar, cinnamon, flour, cornstarch and salt with a wooden spoon and sprinkle over peaches. Stir peaches and dry ingredients together until fully incorporated in with the sliced peaches.
Pour the beer over the peaches, and gently stir to combine.
Place 4 8oz Ramekins on a baking sheet. Divide the filling evenly amongst the Ramekins.
Roll the pie dough out on a lightly floured surface, cut into four squares. Cover each Ramekin with a square of pie dough, crimping the sides. Brush with egg wash.
Bake at 400°F for 18-22 minutes or until golden brown.