Preheat the oven to 400 degrees F.
Line 2 baking sheets with parchment paper.
In a medium sauce pan add one cup of water, the butter, sugar, salt and bring to a full boil until the butter melts.
Add in the flour and baking powder beating vigorously with a wooden spoon until combined. The flour will absorb all the liquid and form a ball.
Continue cooking and stirring the mixture for about 2 minutes as this will get rid of the raw flour taste.
Transfer the dough to the bowl of a stand mixer and beat for about 1 minute. This allows the dough to cool slightly before adding the eggs.
Beat in the eggs one at a time and beat well after each addition while stopping to scrape down the bowl occasionally.
When ready, the dough will be thick and smooth looking.
Spoon the dough into a large pastry bag fitted with a star tip.
Pipe a rosette of 2 inches in diameter directly onto the parchment lined cookie sheet and top with a second layer of rosette. Basically one on top of the other. It will have the appearance of a bird's nest.
Repeat with the remaining dough while spacing the rosettes 2 inches apart.
Bake for 25 to 30 minutes. The pastries should be light golden brown colour.
Allow the pastries to cool completely before filling with the custard.
When ready to fill the pastries, slice them in half with a serrated knife.
Spoon the chilled pastry cream into a piping bag fitted with a star tip and pipe the pastry cream onto the bottom half of the pastries and place the tops back on.
Pipe some more pastry cream over the top centre of the pastries.
Dust generously with powdered sugar and top each with an Amarena cherry