Preheat oven to 400° F.
Place water, butter and salt in a pan.
Bring to a boil. Remove from heat.
Beat in Passover cake flour or matzah meal and mix well with a fork until it forms a ball and does not cling to the sides of the pan.
Return to burner and heat over medium heat for 3 minutes.
Let cool for 10 minutes.
Beat in eggs, one at a time, until fully incorporated.
Place ¼ cup dough on parchment-lined baking sheet. TIP: Moisten parchment paper with a little water before putting the dough on it. This will keep the puffs from drying out and help the eggs to rise the puffs.
Bake for 40 minutes.
Once cool, cut off the top third, scoop out the doughy part, and fill the puffs with whipped cream or a lemon curd filling of your choice. They are also good filled with sorbet or ice cream.