Prepare a 9-inch pie pan by spraying with cooking spray; set aside
For the dough: mix flour, Clabber Girl Baking Powder, sugar and salt. Add butter; cut in with pastry blender or use a food processor, pulsing to break up butter until mixture is crumbly. Add egg and most of water, mixing until a soft dough is formed. Turn out onto a lightly floured work surface and knead a few seconds. Form into a disc, wrap well and chill about 20-30 minutes.
Preheat oven to 425 F.
In a bowl, toss peaches with sugar and peach schnapps. Combine cinnamon, nutmeg and cornstarch and mix in with peaches.
On a lightly floured surface, roll dough to a circle (about 10-12 inches). Transfer to pie pan by folding in quarters and unfolding in the pan. Mound the peaches in center or arrange wedges in concentric circles, leaving a small border and dot with butter. Bake until peaches are bubbly, about 25-35 minutes
Cool and serve.