In a 3-4 quart pan, combine 1 cup water, butter, and the sugar if using; bring to a boil over high heat. Add flour all at once and stir quickly until mixture pulls away from pan sides and masses together.
Remove from heat and stir until flour is incorporated and mixture is smooth. Let cool about 5 minutes, stirring occasionally.
To mix by hand, add eggs, one at a time, to warm butter-flour mixture in pan, beating with a wooden spoon after each addition until dough is smooth and satiny.
To mix with an electric mixer or food processor, scrape warm butter-flour mixture into a bowl.
Add eggs, one at a time, beating or whirling after each addition just until smooth; do not overmix.
Spoon Cream Puff Dough into 10 equal puffs are golden, 25-35 minutes; if baking the sheets at the same time in one oven, switch their positions halfway through.
With a wooden skewer, poke each puff in several places, then continue baking until golden brown, dry, and crisp, 5-8 minutes longer.
Transfer puffs to racks to cool completely.
3. Slice the top third off each puff. Fill each bottom with 1/2 cup of one of the following:
ice cream, chocolate orange cream, lightly sweetened whipped cream flavored with vanilla or a liqueur. Cover with tops, and drizzle each puff with 2-3 teaspoons chocolate chocolate ice cream topping or sprinkle lightly with powdered sugar.
Note: You can make the puffs (through step 2) up to 12 hours ahead; wrap airtight and store at room temperature. Freeze to store longer. To use, place puffs (thawed, if frozen ) slightly apart on a 12- by 15 " baking sheet. Bake in a 400 degree oven until crisp, 5-8 minutes.