Bring water, butter and salt to a rolling boil in a saucepan. Lower heat and add flour all at once, stirring vigorously until mixture pulls away from sides of pan (about 1 minute). Remove from heat and cool until mixture is lukewarm (about 10 minutes).
Beat in eggs one at a time, beating well after each addition until dough is smooth. Drop by the teaspoonful on lightly greased cookie sheet about 2 inches apart.
Bake at 450° for 10 minutes. Lower heat to 300° and bake for 15 to 20 minutes more until puffed and golden.
Blend together filling ingredients. When puffs are cool, make a slit on one side of each puff and fill with ricotta mixture. Makes about 4 dozen.