[header] How to make white chocolate rainbow brownies [title] Double boil the chocolate chips with the butter. [step] ( this means heat them until melted/blended in a pot/bowl on top of another pot with boiling water in it. This keeps them off of the direct heat source so they don't burn). 
[title] Take them off the heat when completely melted. [step] Let cool to room temperature (even a little warmer is fine).