1) Prepare one batch of Vanilla Dream cookies according to the recipe and let cool. Cookies about 3" in diameter work best for the stacks.
2) To make the fruit filling: Wash, peel, and cut the rhubarb into 1/4" slices. Wash and cut the strawberries into 1/4" slices. Grate and reserve the peel from the orange. Remove the white pith from the orange, and cut it into small, bite-sized pieces.
3) Place the cut fruit, grated peel (zest), sugar, and ClearJel in a large saucepan, and cook over high heat for 5 to 8 minutes, until the fruit is broken down and quite liquid. Reduce the heat to low and simmer for an additional 10 to 15 minutes, until nearly all of the liquid has cooked off. Taste and adjust the sugar to your liking.
4) Cool the fruit filling until just warm to the touch. You'll have about 2 cups of filling, so you'll have plenty for filling the stacks, with some left over.
5) To assemble the cakes: Take four like-sized cookies and spread the tops of three of them with about 2 teaspoons of the filling. Stack the cookies with filling between, topping the stack with the plain cookie. Repeat with the rest of the cookies and filling. Barring too much breakage, you should end up with 7 to 8 stacks.
6) Once you have your "cakes" stacked, cover each cake completely, sides and top, with the fresh whipped cream. Place the frosted cakes on a tray or plate, and place in the refrigerator overnight, lightly draped with plastic wrap.
7) As the cakes sit, the filling will soften the cookies to a moist, tender consistency. One stacked cake can serve one person as a snack, or two people after a rich dinner.
Yield: about 7 small cakes.