Gather all your ingredients and preheat your oven to 400°F (200°C). Make sure your butter is unsalted for the best flavor contrast in the pastry base.

In a saucepan, combine water and butter over medium heat. Stir until the butter is melted, and bring the mixture to a boil.

Once boiling, reduce the heat and swiftly add the flour and salt. Stir vigorously for about 1-2 minutes until the mixture forms a ball and pulls away from the sides of the pan.

Remove the saucepan from the heat and allow the dough to cool for about 5 minutes.

Begin adding eggs one at a time, beating with a wooden spoon or mixer until each egg is fully incorporated before adding the next.

Transfer the dough into a piping bag fitted with a large round tip. Pipe swirls or small mounds onto a parchment-lined baking sheet.

Place the baking sheet in the preheated oven and bake for 20-25 minutes until the puffs are golden brown and completely risen.

While the pastry shells cool, whip the heavy cream with eggnog and vanilla extract in a mixing bowl until soft peaks form.

Once the pastry shells have cooled completely, use a sharp knife to cut them open and gently pipe or spoon the eggnog cream filling into each shell.

Before serving, dust the top of the filled Eggnog Cream Puffs with powdered sugar.