Step 1: Preheat oven to 400°F (200°C) and line two baking sheets with parchment paper.
Step 2: In a medium saucepan, combine water, butter, and salt. Bring to a boil over medium heat.
Step 3: Remove from heat and immediately add flour all at once. Stir vigorously until mixture forms a ball.
Step 4: Let dough cool for 5 minutes, then add eggs one at a time, beating well after each addition until smooth.
Step 5: Drop dough by rounded tablespoons onto prepared baking sheets, spacing 2 inches apart.
Step 6: Bake for 20-25 minutes until puffed and golden brown. Turn off oven, prop door open slightly, and let puffs dry for 10 minutes.
Step 7: For custard filling, whisk together milk, sugar, cornstarch, egg yolks, vanilla, nutmeg, cinnamon, and cloves in a saucepan.
Step 8: Cook over medium heat, whisking constantly, until thickened (about 8-10 minutes). Remove from heat and let cool completely.
Step 9: Whip heavy cream with powdered sugar until stiff peaks form. Gently fold into cooled custard.
Step 10: Cut cooled puffs in half horizontally. Pipe or spoon filling into bottom halves, replace tops, and dust with nutmeg.