Prepare a square 8x8 baking dish by lining it with aluminum foil or parchment paper and buttering or spraying with non stick cooking spray

Place sweetened condensed milk in a medium saucepan and heat over medium heat stirring constantly until heated through. Heat for about 3-5 minutes being careful not to boil.

Add in white chocolate chips and continue stirring until the chips are completely melted.

Remove the sauce pan from the heat and add in butter and sugar cookie mix. Stir until both are well incorporated

Pour the fudge mixture into your prepared square pan and place sprinkles across the fudge in an even layer.

Place in the refrigerator for at least 4 hours.

Remove from the refrigerator about 30 minutes before cutting. Cut into 16 pieces

Store in an airtight container.