In a medium saucepan, heat water, butter and salt to a rolling boil; mix in flour by hand until mixture forms a ball. Remove from heat; cool 5 min. Beat in eggs by hand, one at a time, until smooth. Drop 6 evenly sized mounds 2" apart on a parchment-covered baking sheet. Bake in a preheated 400° oven until puffed and golden-brown (35-40 min.). Carefully remove from baking sheet; cool completely on a wire rack. Cut off tops; remove soft dough from inside of both halves. Fill bottom half of each puff with Vanilla Pastry Cream (click here for recipe); replace tops, dust with powdered sugar and drizzle with chocolate or caramel sauce, if desired. Serve immediately.