Melt the white chocolate in a microwave-safe bowl at 50% power for 30 seconds, then stir. Continue heating in 15-20 second intervals until the chocolate is smooth.

Mix in the mini marshmallows gently to coat them with chocolate.

Spread the marshmallow-chocolate mixture onto a lined baking sheet, creating an even layer about half an inch thick.

Before the chocolate sets, sprinkle with decorative sprinkles and gently press them in.

Let the bark cool at room temperature for 1-2 hours until solid.

Once set, slice into squares or triangles and serve or package for gifts.