1. Preheat oven to 400°F. Prepare baking sheets with parchment paper. Set aside.
2. In a heavy bottomed medium saucepan, bring milk, water, butter, sugar and zest to a boil.
3. Once mixture is at a rolling boil, add all of flour at once, reduce heat to medium and start to stir mixture quickly with a wooden spoon. After one minute, reduce heat to low and stir for 3 more minutes. Dough will be smooth and shiny.
4. Transfer dough into a bowl of a stand mixer fitted with paddle attachment. Beat dough for 5 minutes to cool.
5. Add the eggs one at a time, beating for one minute after each egg has been added.  The dough will separate, but will come back together after some time.
6. Place dough into a piping bag with a large star tip opening. Pipe dough onto parchment lined baking sheets in 3 inch circles. Use a moistened finger to touch up any jagged dough edges, if necessary.
7. Bake for 25 minutes, or until puffed and golden brown. Rotate pans halfway through baking time. Allow to cool; fill with Orange Hazelnut Filling.

Orange Hazelnut Filling

1. In the bowl of a stand mixer, beat the butter, hazelnut spread and orange juice until smooth. Add the heavy cream a little at a time; beat for 3 minutes until fluffy.

2. Slowly add in the confectioners sugar and beat on medium high speed until smooth.