Preheat oven to 425°F (220°C). Line 2 baking sheets with parchment paper, or silicone mat.

In a medium saucepan, combine 2/3 cup (150ml) of water, butter, sugar and salt and bring the mixture to a boil over medium high heat. Once the butter is melted and mixture is boiling, add the flour all at once, reduce the heat to medium. Using a wooden spoon, continuously stir the mixture. The dough will start to form into a ball. Keep mixing for another 3-4 minutes until light crust forms on the bottom of the pan.

Transfer the dough into a mixing bowl with paddle attachment and mix it for a few minutes on low speed until the mixture is at room temperature. (Alternatively, you can use a wooden spoon. Mixer is not required here!) Add the eggs one at a time, beating well after each addition. This will help to get egg absorbed into the dough quicker. The dough should not be too runny, yet not too thick.

Transfer the batter into a pastry bag and pipe into 1.5-inch rounds couple inches apart. Level peaked tops with wet fingertip, if needed.

Bake for 25-30 minutes, rotating the sheets top to bottom and back to front half way. The pastry shells should be golden brown, crispy and puffed up. Transfer the shells onto a cooling rack to cool completely. (If the pastry shells fall flat when you remove from oven, it means they are under-baked. Simply put it back into the oven and bake for another 3-5 minutes, or until they puff up again.)

To make the filling, whip the heavy cream until hard peaks form in a mixing bowl with whisk attachment. Fold in Nutela and gently mix until smooth. Transfer the filling into a pastry bag with small round tip (I used Wilton #7 round tip). 

When ready to serve, pipe the filling into each pastry shell through a small hole on the side. (Mine usually have a small hole somewhere, but you can also make a small slit with a knife.) Alternatively, you can cut the pastry shells horizontally and fill the shells that way.

To make the glaze, microwave the cream for 30-60secons, or until hot. Place the chocolate chips in a small bowl and pour the hot cream over it. Let is sit for a minute and then mix until smooth. Dip the filled cream puffs into the chocolate ganache and arrange them on a platter. Serve immediately.