Cream sugar and butter. Add egg, flavoring and flour.
Pinch off small pieces of dough about the size of a walnut. Put them in the center of a sandbakkel tin (tiny, individual fluted tart shell tins) and press thinly and evenly into sides and bottom. Place the tins on a cookie sheet and bake in a preheated 375° oven about 12 minutes.
When cool, tap gently on the bottoms of the tins and the tarts will drop out easily. They are very fragile, so remove them carefully. Fill with whipped cream and strawberry preserves just before serving.