> Add pinch of salt to the water and boil it well.
> Add the Butter to the pan and make it melt.
> Then add the flour to the boiling butter water and knell it well, until it's not stick to the pan anymore.
> Finally take out the pan and add eggs one at a time and beat it well.
> Pipe the equal amounts on a baking sheet and bake it in 200C for 20-30 minutes.
> Once the pastries are cooled enough to pipe the filling.
For making the tower you need to caramel the sugar and stack them all in to a shape of pyramid. That's what you called a Croquembouche.
Unless you still can use the pastries separately, it's just Cream Pastires