A great summer dessert–hot or cold. Wonderful crust for rhubarb. Birch Hill Inn, Manchester, Vermont
Mix together flour, oats, brown sugar, butter, and cinnamon until crumbly. Press half of crumbs into 9-inch-square or 11x7-inch pan. Cover with rhubarb. In a saucepan combine granulated sugar, cornstarch, water, and vanilla and cook, stirring, until thick and clear–about 10 minutes. Pour over rhubarb, top with remaining crumbs, and bake at 350 degrees F for 1 hour. Cut in squares and serve with whipped cream or ice cream.