Combine the peanut butter and confectioners' sugar in a microwave-safe bowl. Heat the mixture until the peanut butter melts, about 1 minute. Place the chocolate chips in a separate microwave-safe bowl; melt the chips in the microwave, about 1 minute.
Arrange the tortilla chips into an even layer on a baking sheet. Drizzle the peanut butter mixture and the melted chocolate over the chips. Scatter the marshmallows and coconut over the chips.
Place under preheated broiler until the marshmallows begin to brown, 2 to 3 minutes. Serve hot.