What is the best and fastest way to liquify Nutella chocolate spread?
Heating it up in the microwave will temporarily make it runnier, but then it will go back to its original consistency. Here are some ways that may work for you:


Add some neutral flavored oil: just a bit though or it will get greasy
Add chocolate syrup: chocolate syrup is very runny will thin it out while still keeping the chocolate flavor. Hershey's is available in the US and UK, Tate and Lyle makes one in the UK. Not sure where you are but there will likely be something available
If you can't find chocolate syrup try making a very thick chocolate milk with some cocoa powder or chocolate milk powder