In the bowl of a stand mixer fitted with paddle attachment, place 2.5 pounds cookie mix, 3 oz soft unsalted butter and 6 oz cold water. Mix on 1st speed, scraping down the bowl often until mixture resembles a thick paste and has no lumps. By hand, stir in 2 oz sprinkles. Using a black handled #30, 1oz scoop, scoop cookie dough onto parchment lined sheet trays (1.4 oz dough pucks). Place in cooler for minimum of one hour. Overnight is optimal. Once dough is completely chilled, place 3 mini marshmallows in the center of each dough puck and wrap dough around marshmallows (pucks finished weight will be 1.5 oz). Bake at 350°F for 10 minutes or until cookies are golden brown around the edges. Place 2-3 marshmallows on top of cookies just before removing from the oven.