This is a Pampered Chef Family Heritage Stoneware 12-Cup Muffin Pan.  Made from natural, unglazed stoneware that becomes more nonstick with use.  It is oven-safe and microwave-safe up to 450°F (230°C).  The pan is also freezer-safe.  Each of the 12 wells holds a standard \(\frac{1}{2}\)-cup portion.