Add butter, milk, water, sugar and vanilla to a pot and bring to a boil on the stove.
Once everything is melted together, reduce heat to low and add in the flour.
Mix the flour in thoroughly and a dough ball will form.
Remove the pot from the stove and add the eggs one at a time until well blended.
Add dough to a piping bag fitted with a 1M or large star tip and place in the fridge for 10-15 mins to stiffen up a bit.
Combine sugar and cinnamon and set aside
Heat the oil to 350
Squeeze dough into hot oil.
Fry on each side for 3-4 mins until golden brown and cooked all the way through.
Remove from the oil and drain.
Toss in cinnamon sugar mix fully coating the churros.
Heat Nutella in a piping bag for 10-15 seconds.
Use a skewer to create a hole in both ends of the churro
Squeeze in the warm Nutella into the churros
Best when served warm