To make crust: Preheat oven to 350°. Combine graham cracker crumbs, sugar, cinnamon and margarine in a bowl and mix well. Spoon into an 11-inch round (or 9"x11" rectangular) tart pan and press evenly onto sides and bottom. Bake 10 minutes; remove from oven and cool to room temperature on a wire rack.

To make filling: Heat the fat-free half-and-half, pumpkin, brown sugar, salt, cinnamon and nutmeg in a double boiler (or a heatproof bowl over simmering water) until hot, about 5 minutes. In another bowl, whisk the egg yolks and Egg Beaters. Stir half of the pumpkin mixture into the eggs, then pour the egg-pumpkin mixture back into the top of the double boiler and stir well. Heat over simmering water for another 4 to 5 minutes, until the mixture begins to thicken, stirring constantly.

Dissolve the gelatin in 1/4 cup cold water. Remove the pumpkin mixture from the heat and add the gelatin, banana and orange zest. Mix well. Set aside to cool. Fold the fat-free whipped topping into the pumpkin mixture (flavor whipped topping with 1 teaspoon of vanilla, if desired). Carefully pour into the cooled tart shell and chill for 2 hours or overnight.

To prepare garnish: If desired, add 1 teaspoon of vanilla and 1/2 teaspoon of orange zest to the fat-free whipped topping.

Remove tart from refrigerator; using a pastry bag or small spoon, decorate edge of the tart with whipped topping. Sprinkle with extra orange zest if desired. Serve immediately.

How Art reduced the fat: Art substituted low-fat margarine and fat-free half-and-half for the butter and heavy cream called for in the original recipe. Fat-free whipped topping replaced the cream used for garnish and Egg Beaters took the place of a portion of the egg yolks. Art's changes reduced the amount of fat by 10 grams!