Preheat oven to 375° Fahrenheit. Line 9x13 baking pan with parchment paper, leaving excess parchment paper hanging over sides of pan. Excess paper will act as "handles" to help remove cookies from pan after baking.
Add 2 16-ounce packages refrigerated sugar cookie dough and ¾ cup dried cranberries to large mixing bowl. Gently fold cranberries into cookie dough until fully incorporated and evenly distributed.
Transfer cranberry sugar cookie dough to prepared pan. Spread and/or press dough out into flat layer covering parchment paper, making sure dough layer is evenly thick across entire pan.
Place pan in preheated oven. Bake cookie dough 20 minutes, then begin checking doneness. Continue baking cookie dough as needed until edges of dough layer are set and center of cookie dough surface is slightly golden-brown. Be very careful not to over-bake cookie dough. If unsure, remove pan from oven.
When cookie dough layer is ready, remove pan from oven and place on top of wire cooling rack. Let cookie layer cool in pan until room temperature.
Once cookie dough layer is cooled, add 12 ounces white chocolate chips and ½ cup unsalted butter to microwave-safe bowl. Microwave chocolate and butter on 50% power in 20-second increments, stirring mixture after each increment, until chocolate is completely melted and mixture is smooth. Do not over-heat chocolate and be very careful not to get any water in mixture.
Once chocolate mixture is smooth, pour mixture directly on top of cookie dough layer in baking pan. Spread chocolate mixture out across surface of cookie dough layer and into corners in one even layer, covering cookie dough completely.
Once chocolate ganache layer is smooth, sprinkle white sugar pearls across surface as desired. Place baking pan in refrigerator and chill cookie bars, uncovered, 30 minutes or until chocolate layer has hardened.
Once chocolate layer has hardened, remove baking pan from refrigerator. Carefully loosen cookie bar sheet from pan, using excess parchment paper as handles to lift cookie bars out of pan as needed. Set parchment paper and cookie bar sheet on counter, cutting board, or other flat work surface.
If desired, use knife to carefully trim away outer edges of cookie bar sheet. Slice sheet into 4 rows of 4 cookie bars. Serve as desired.