In a small heavy bottom saucepan on medium heat, add water, butter and sugar. Once the mixture is boiling, add flour and stir with a spatula. Stir until a there is a thin coating of dough on the saucepan.
Spoon dough into a large bowl. Stir for 1 minute to cool. Add two eggs, one at a time, mixing in between each addition. It might look like it's curdled, but keep mixing, it'll eventually come together!
Spoon dough into a piping bag and pipe 3 inch circles on a parchment- lined baking sheet. Brush each choux pastry with egg wash. If you had any points you can use the brush to sooth out the choux. Using a spray bottle, mist the baking sheet with water once or twice. You can also dip you hand in water and flick droplets onto the baking sheet if you don't have a spray bottle.
Bake at 425 F for 12 minutes, then turn the heat down to 375 F and bake an additional 25 minutes or until the choux pastry is golden brown. Do not open the oven door while they bake, you want the heat to dry out the center of the eclairs. Once baked, poke a hole on the underside of each choux pastry and let cool.
Fit and mixer with a whisk. Add all the ingredients in the mixing bowl and whisk on high until stiff peaks. Fill a piping bag with the whipped cream and set aside until ready to assemble.
Assemble: Cut the top off each choux pastry and fill the bottom halves with whipped cream and berries/fruit. Place the other half on top and dust with additional powdered sugar. Enjoy!