Combine the 1 1/4 cups flour and granulated sugar in a bowl. Add the butter to the bowl. With a pastry cutter, 2 forks or your fingertips, work the butter into the flour mixture until thoroughly distributed. Add the water and mix until just incorporated (dough should be a little crumbly).
Lightly grease a 9-inch false-bottom tart pan with oil spray. Transfer dough to the tart pan, and then firmly and evenly press it into the bottom and sides of the pan. Refrigerate tart shell 20 minutes.
Bring a pot of water, large enough to completely submerge the peaches, to a boil. Mark a shallow X into the blossomed end of each peach. Cook in the boiling water 1 1/2 to 2 minutes, until the skins start to loosen. Plunge peaches in cold water and pull away the skins. Cut peaches in half and remove the pits. Now cut each half peach into 4 wedges and set on a plate.
Preheat oven to 350°F. Beat the eggs in a medium bowl. Mix in the brown sugar, 1 Tbsp. flour, sour cream, vanilla and spices. Spoon this mixture into the tart shell.
Arrange the peach wedges in a spiral over the filling. Bake tart 60 minutes, or until the filling is set. Cool tart to room temperature.
To serve, unmould the tart, dust with icing sugar, cut into wedges and plate. Top servings of the tart, if desired, with a dollop of whipped cream and a mint sprig.
Recipe Options: Instead of peaches, use nectarines in this recipe.