Pour the milk chocolate into the Thermomix and chop for 10 seconds / speed 10 (possibly a little longer or shorter, fine pieces should be created). Now add the Nesquick and cocoa powder and mix for 2 seconds / speed 10, then add the cream and whip for about 15-20 seconds / speed 6.
The preparation with cream depends on the weather, so it is advisable to switch off the Thermomix immediately if the noise changes.