In large bowl with electric mixer, beat cream cheese until fluffy, about 1 minute.
Add eggs, one at a time, beating until well combined, scraping the edges if necessary.
Add sugar and beat until well combined.
Add heavy cream and vanilla and beat until well combined.
Add Nutella and beat until well combined.
Chop remaining 8 Oreos and fold into cheesecake mixture.
Fill each cupcake liner to top.
Bake in preheated oven for 22-26 minutes, until centers just loosely jiggle.
Let cool in muffin pan for 30 minutes, then place in refrigerator to cool completely, about 2 hours.
Once completely cooled, make the whipped cream.
Place heavy whipping cream and powdered sugar in large bowl with electric mixer.
Beat on high until stiff peaks form.
Scoop into large plastic baggie (which is what I did) or pastry bag, and pipe frosting onto cupcakes. If you use plastic baggie, cue one edge off to pipe through.
Top with chopped Oreos and hazelnuts.
Store in refrigerator.