Prepare the Crust:

Place the 3 cups flour, salt and sugar in the bowl of a food processor. Pulse 3-4 times to incorporate. Dice the 1 1/2 sticks of butter into small pieces. Place the butter and shortening in the bowl of the food processor along with the flour mixture. Pulse 10-12 times, until butter pieces are about the size of a pea and are fully incorporated into the mixture. Add the ice water, 1 tablespoon at a time, into the mixture, pulsing to incorporate. Continue adding the water in this manner until the dough comes together to form a ball. (Not all of the water may be needed to help the dough come together.) Wrap the dough in plastic wrap and chill for at least 1 hour.

Prepare the Filling:

Place the peaches, sugar, flour, cinnamon and nutmeg in a large microwave-safe bowl. Set aside until a syrup forms. Microwave the mixture on high power in 90-second intervals, stirring after each interval, until mixture boils and thickens. Stir in the vanilla extract and 1/4 cup butter until the butter melts.

Prepare the Cobbler:

Preheat oven to 475 degrees.

Cut the prepared dough in half. On a well-floured surface, roll one of the halves to a 1/8-inch thickness and trim into an 11x7-inch rectangle.

Spray an 11x7-inch baking dish with nonstick spray. Pour half of the peach mixture into the bottom of the pan, and top with the prepared dough rectangle. Bake for 10-12 minutes, or until crust is lightly browned. Spoon the remaining peaches over the baked pastry.

On a floured surface, roll the remaining pastry to a 1/8" thickness. Cut the dough into 1-inch strips, and arrange the strips in a lattice over the peaches, trimming the strips as needed. Bake an additional 15-18 minutes, or until browned and bubbly. Serve warm with a scoop (or two!) of vanilla ice cream.