MELT chocolate chips in microwave or double boiler; set aside and let cool to room temperature.
SIFT together cocoa powder and confectioners’ sugar.
CREAM butter and confectioners’ sugar/cocoa powder mixture using the whisk attachment on a stand mixer or a hand-held mixer. If mixture seems too dry, add a tablespoon or two of heavy cream to smooth it out.
SCRAPE down the sides of the bowl and add melted, cooled chocolate.
WHIP mixture until it’s smooth and silky. If it seems too thick, add heavy cream one tablespoon at a time to reach desired consistency.