Shop › Fort Mason Monster Cookie Image 1 of 1 Fort Mason Monster Cookie $35.00 Shortening base, M&Ms, oats & chocolate — a low-and-slow bake. Key ingredients: All-purpose flour, Baking soda, Fine sea salt, Whole milk powder, Vegetable shortening / margarine, Unsalted butter, room temp. Sold by the dozen. Add To Cart Added! Shortening base, M&Ms, oats & chocolate — a low-and-slow bake. Key ingredients: All-purpose flour, Baking soda, Fine sea salt, Whole milk powder, Vegetable shortening / margarine, Unsalted butter, room temp. Sold by the dozen.