Let’s start with a premise: strufolini are not popular and may be confused with the more popular “struffoli”, which are a completely different thing and are Neapolitan pastries. I have tried strufolini in an old restaurant which was in Milan some years ago and which does not exist anymore. The restaurant ended their activity, but luckily I have eaten in that place some years ago and still keep photos of these strufolini, which are basically rolls of pizza dough topped with hazelnut cocoa spread. Not so many places do this exact recipe, which has maybe even reinterpreted by the restaurant itself.
A very simple recipe, inspired to the tradition of Roman street food, proposed by an old restaurant I was able to try years ago. I still remember that dinner and the strufolini made in this way.
This is the old Google Maps page of the restaurant:
MICS
Via Pietro Maroncelli, 15, 20154 Milano MI
https://goo.gl/maps/jBhGBNbZVnvFfMeJ9
At the same address, now, there is a seafood restaurant.