Line a 9*5 inch (23*13cm)pan with parchment paper if you are not using a non-glass one so your pan won't be damaged while scooping the ice cream. Set aside the pan.
First make the candied hazelnuts and chop into small pieces. Set aside.
Place the heavy cream into a mixing bowl and beat with whisk attachment at medium-high speed until stiff peaks form for almost 2 minutes. Don’t over whip. If you over whip heavy cream, it turns into butter.
Fold the condensed milk into heavy cream in 3-4 batches. Alternatively, you can slowly pour the condensed milk into heavy cream while the machine is working on low speed.
Pour half of the mixture into the loaf pan. Reserve ⅓ of chopped caramelized hazelnuts (70grams) and set aside. Sprinkle half of the remaining caramelized nuts on top(70grams). Mix the mixture with a spoon. Then pour other half mixture on top and sprinkle other half caramelized hazelnuts on top(70grams). Mix the mixture with a spoon again.
Keep in the freezer at least for 6-8 hours or until it firms up. It is even better if you can freeze overnight. Remove the ice cream from the freezer when ready to eat, as it melts easily. When serving, sprinkle the caramelized hazelnuts on top that you reserved before. You can keep the ice cream in the freezer up to 2 weeks.