How to make pistachio liqueur step by step

• Heat the heavy cream in a saucepan.
  150 ml heavy cream
• When it's hot - but not yet boiling(!) add the pistachio cream to it.
  approx 200 g pistachio cream
  
• Mix together until you get a uniform sauce.
  
• If the sauce is lukewarm (not hot) then add the vodka to the saucepan and mix thoroughly.
  250 ml vodka
  
• Pour the liqueur into a bottle and ideally let it rest for a day for the flavors to meld together.
• After standing for a longer period, the liqueur may slightly separate - in that case, simply shake it vigorously.