Stir together water and 1/4 cup sugar until sugar dissolves.
Pulse raspberries in a food processor until coarsely chopped. With machine running, pour in sugar-water; pulse until mixture is smooth. Transfer to an airtight container, and freeze until firm, about 30 minutes.
Whisk cream and remaining tablespoon sugar until soft peaks form.
Scoop sorbet into 4 glasses, and top with whipped cream.
This is an awesome recipe. It comes together so simply, yet has such a vibrant taste. I've made this a bunch of times already. Most recently, I added semisweet chocolate chunks, which turned out great.
A friend brought this sorbet to a dinner party and I made it myself this morning before work. It is amazing. The color alone is enough to make it a keeper. The whipped cream is nice but not really necessary. How many desserts only have a quarter cup sugar and have flavors that explode in your mouth?
I will definitely make it again (and again) but will try to use a submersion blender or food processor. I think the conventional blender is one of the most useless tools in the kitchen.