In a microwavable bowl, heat Ghirardelli chips on high for 45 seconds; remove and attempt to stir.(Chips may still be too stiff to stir.)
Return chips to microwave and heat for another 20 seconds; remove and attempt to stir.
Return chips to microwave and heat for 10 seconds; stir.
Repeat until chips are just soft enough to turn completely smooth when stirred briskly. (Avoid overheating, because this will cause the chocolate to harden up permanently.)
(NOTE: This recipe utilizes a 1100 watt microwave. If your microwave is less than 1100 watts, you may need to heat your chocolate a slightly longer period of time; if your microwave is greater than 1100 watts, you may need to reduce the heating time.)
Once chocolate is melted enough to turn completely smooth when stirred, remove from microwave.
Add milk, 1 tsp at a time, mixing well after each addition. (Using room temperature milk will help keep the melted chocolate from hardening up.)
Add powdered sugar and stir until well combined. Tiny amounts of additional milk--1 tsp at a time--may be added at this point if needed to achieve desired texture for easy spreading. Enjoy!
Notes
Recipe Yield: About 1 1/2 cups rich chocolate frostingNote: Cover frosting tightly with plastic wrap until ready to be used. This should be done by pressing a layer of plastic wrap down onto the surface of the frosting to keep air from getting to it.Because of the high chocolate content of this frosting, it may solidify quickly as it cools to room temperature.If this happens, simply slip it back in the microwave for 10-20 seconds to soften it back up.