In a stand mixer with whisk attachment combine whipping cream, sugar and matcha powder. Begin mixing at a low to medium speed until powder is mixed in, then increase speed to high. Watch for mixture to create stiff peaks. This happens fairly quickly so don't move away from the mixer. If it mixes too long you'll create butter or your whipped cream will have a strange texture.
If you're adding in chocolate chips wait until the whipped cream is complete then add in your chips. If you're using chopped chocolate chips, chop them to the desired size first, then add them to the mix. You can either use the stir setting on your mixer or gently fold them in by hand.
Store it in the refrigerator until you're ready to use it.