Clean and rinse berries. If they are large cut in halves or quarters.
Bring water to a boil over medium heat. Add sugar and strawberries and simmer until berries are tender, about 8 minutes. You will still have lumps of berries. If you want a smooth consitency, break the fruit up by pushing the berries with the back of a spoon on the side of the pan.
Dissolve cornstach in a little water and add to fruit, stirring constantly. Add vanilla or zest if desired (one or the other not both).
Bring to rolling boil, stirring constantly. Continue stirring and allow pudding to boil a few minutes. The pudding should no longer be cloudy and regain its shine and gloss.
Transfer to a bowl and place in the refrigerator until thouroughly cool. Depending on the bowl size and shape, this could take several hours.
If you are planning to substitute part of the sugar (would not suggest all) with baking Splenda, add the splenda to the bowl just before cooling.
Optional serving ideas: Top with whipped cream, Cool Whip or vanilla yogurt. Chocolate shavings or a dusting of cocoa are also nice.