Step 1Position a rack in the center or just below the center of the oven and heat the oven to 400 degrees. Grease the corners of 2 baking sheets and line the sheets with parchment paper; or line them with foil and grease the foil.
Step 2In a small saucepan, combine the water and butter over medium-low heat, cooking until the butter melts. Increase the heat and bring the mixture to a boil. Remove from heat and add the matzo cake meal, all at once, mixing very well. Return the pan to low heat and cook, stirring constantly, until the mixture is a thick paste, about 1 minute. Remove from heat and transfer the mixture to the bowl of a stand mixer or another large bowl and set aside to cool for 5 minutes.
Step 3Beat one egg into the mixture until completely incorporated, using the paddle attachment (if using a stand mixer) or a wooden spoon (by hand). Continue beating in the eggs, one at a time, until fully combined and the dough is smooth.
Step 4Take rounded tablespoons (about 1 1/2 measuring tablespoons each) of dough and place the dough onto baking sheets, spacing each rounded mound about 1 ½ inches apart. If there are points on the mounds, moisten your finger with water and push them down to smooth out.
Step 5Place the baking sheets on the rack in the center of the oven. (If 2 baking sheets don’t fit on the same rack, reserve the second baking sheet at room temperature.) Bake for 15 minutes.
Step 6Reduce the oven temperature to 375 degrees and bake the puffs until golden and firm, 14 to 20 more minutes.
Step 7Turn off the oven and wedge the oven door open with a wooden spoon. Leave the puffs in the oven for 30 minutes to give them time to dry out.
Step 8Remove the puffs from the oven. Using the point of a paring knife, pierce each puff at the center of one side to allow steam to escape.
Step 9If you have a second batch of puffs to bake, reheat the oven to 400 degrees. Bake, cool and pierce the second batch of puffs as above.
Step 10Like other cream puff shells, those made for Passover are best on the day they are baked. You can store unfilled shells for a day in an airtight container at room temperature. If you’re keeping the shells for longer than that, it’s best to freeze them; however you keep them, it’s worth heating them in the oven or toaster oven at medium or medium-low heat to restore their freshness. After you have filled the cream puff shells, you can keep them in a closed container in the refrigerator for up to a day.