Preheat oven to 375 degrees F

Line baking sheet with parchment paper or silicone mat

In a large saucepan add water, butter, salt, and sugar

Bring to a boil over medium-high heat and remove from heat

Quickly stir in flour with a wooden spoon until well combined, about 1 minute

Return pan to stove and continue cooking, stirring constantly until a film forms on the bottom of the pan

Remove from heat and transfer mixture to a large bowl, let cool slightly

Add 4 eggs, one at a time, stirring to incorporate each egg completely before adding the next egg

Make an egg wash with the remaining egg and 1 tablespoon water, whisk together and set aside

Transfer dough mixture to a large disposable decorator pastry bag fitted with a large round tip.

Pipe circle 2 inch in diameter onto parchment paper

Moisten your finger with water and gently smooth out the pointed peaks if necessary

Brush surface of cream puff with egg wash

Bake at 375 degrees F for 25-30 minutes or until puffs rise and are golden brown

Remove from oven and allow to cool completely on wire racks

Filling

While cream puffs are cooling, place large mixing bowl and beaters in freezer to chill

When the cream puffs are cooled, remove bowl and beaters from freezer

Add heavy cream and beat until peaks form

Add powdered sugar and vanilla and continue beating until stiff peaks form

Fit a pastry bag with a tip and fill with cream

Cut top portion of the cream puff off with a knife, then fill with pastry cream, replace top

Or you can leave the cream puff whole and fill

Add cream no more than 4 hours prior to serving

Dust with powdered sugar or berries, if desired

Store in refrigerator