In a large bowl combine the all of the ingredients for the filling and stir together gently until combined. Set aside while you make the crust.

Preheat oven to 425° F. Spray an 8 inch cast iron skillet with cooking spray or brush with melted butter.

In a medium sized bowl combine the flours, sugar, baking powder, cinnamon and salt. Add in the cold cubes of butter and work them into the flour with your fingers or a pastry cutter until everything comes together and resembles breadcrumbs.

Start with 1/3 cup of milk and pour it into the mixture stirring together quickly and gently until the dough comes together. If the mixture seems dry and won't come together, drizzle in more milk until it does.

On a lightly floured surface, roll or pat the dough out until it's about 1/4 inch thick. Place it into the prepared skillet allowing the dough to hang over the edges.

Fill the crust with the peach mixture and fold the hanging dough towards the center leaving the middle uncovered. Brush the crust with milk and sprinkle with sugar. Bake for 25-30 minutes or until the crust is golden brown. Cool for 10 minutes before serving with vanilla ice cream or whipped cream.