Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.

In a medium saucepan, combine 1 cup of water and 1/2 cup of butter over medium heat until it comes to a full boil.

Add in 1 cup of all-purpose flour all at once while stirring vigorously until a smooth dough forms.

Transfer the warm dough to a mixing bowl and let it cool, then incorporate 4 room-temperature eggs one at a time.

Using a piping bag, pipe small mounds (1 to 1.5 inches in diameter) onto the prepared baking sheet.

Bake the cream puffs for 20-25 minutes until puffed and golden brown.

Remove from the oven and cool the cream puffs on a wire rack.

In a mixing bowl, whip 1 cup of heavy cream, gradually adding 1/4 cup of sugar and 1 teaspoon of vanilla extract until soft peaks form.

Once cool, cut the puffs in half and fill them with the creamy vanilla filling.