National Strawberry Sundae Day is observed every year on July 7th. Traditionally, sundaes consisted of vanilla ice cream, a sauce of some sort (chocolate, cherry, strawberry, etc.) maybe some candy sprinkles and/or chopped nuts, whipped cream, and a cherry on top, but you may use whatever flavor of ice cream you wish, the sundae police aren't going to come and beat you down for not using vanilla (they don't do that anymore).
Here is a video showing how to make a basic strawberry sauce that can be used for your strawberry sundae. You can omit the balsamic vinegar if you don't have any on hand, or substitute it with a teaspoon of vanilla extract, but add vanilla extract at the end, after cooking.
Photo: Strawberry Sundae at Saint's Alp
Originally uploaded by kaikai666