Preheat oven to 350°. Line a baking sheet with a nonstick baking mat or parchment paper; set aside.
In a large bowl, mix together all ingredients with 1 cup water to form a dough. Roll out mixture between two sheets of plastic wrap to 1/4-inch thick; remove plastic wrap and cut out biscuits with a 3 1/2-inch bone-shaped cookie cutter. Reroll scraps and continue cutting out biscuits.
Space biscuits 1 inch apart on prepared baking sheet. Bake for 30 minutes until nicely browned and firm.
Transfer biscuits to a wire rack. Turn off oven and place biscuits on wire rack in oven overnight. Remove from oven and store in an airtight container up to 2 weeks.