Preheat oven to 425. Bring water, butter, salt and sugar to a boil in a small saucepan. Remove from heat and immediately pour all of the flour at once. Beat vigorously with a wooden spoon until thoroughly blended and the mixture forms a mass. Form a well in the center of the paste and break one egg into the well. Beat into the paste for several seconds until it has absorbed. Continue with the remaining eggs, beating them in until blended and smooth. Fill a pastry bag with the warm Choux paste. Squeeze onto baking sheets about 2 inches apart. Brush the tops with a beaten egg. Bake for about 20 minutes or until doubled in size, golden and crusty to the touch. Remove from the oven, pierce each puff with a sharp knife and return to the turned-off oven with the door open for 10 minutes. Cool on a rack before filling with pastry cream, whipping cream or ice cream. Top with melted semi-sweet chocolate. 

To make the puffs into a heart shape, simply pipe two tapered mounds for each puff as follows: