Preheat oven to 400℉. Place rack in the center of oven.
Line baking sheet with parchment paper.
Whisk together flour, salt and sugar. Set aside.
In a large heavy saucepan, over medium high heat, combine water and butter. Bring to a boil.
Remove saucepan from heat.
Add flour mixture all at once, and stir with wooden spoon.
Lower heat to medium low.
Return saucepan to the stove and continue to stir until mixture forms a smooth ball (1-2 minutes).
Remove from heat.
Transfer mixture to the bowl of stand mixer or large mixing bowl.
Let cool for about 2 minutes.
Beat with paddle attachment or hand held mixture for a few minutes in order to cool down the mixture (1-2 minutes).
Add eggs, one at a time, mixing well after each addition.
Spoon dough into pastry bag fitted with open star tip.
Pipe dough into 2" nests on parchment paper.
Place in pre-heated oven for 35-40 minutes, until golden brown.
During last 5 minutes of baking, pierce the outer shell with a sharp knife allowing the steam to escape. Leave the oven door ajar.
Remove the pastry shells from the oven. Can cut in half or leave as is.
When shells are cool, use pastry bag fitted open star tip to pipe pastry cream onto the shells; cover with the top and pipe another tablespoon or so over the top OR make a small hole and pipe pastry cream directly in the cavity; top with more pastry cream.
Top with an amarena (cherry) and a dusting of icing sugar.