Put strawberries in a small saucepan. Add 1-1/2 tablespoons of granulated sugar substitute and 1½ teaspoons of lemon juice. Cook on high just until the mixture starts to boil. Turn heat to medium and stir frequently, mashing berries with a spatula, to keep from burning or sticking to the bottom of the pan. After about 15 minutes, most of the liquid should be cooked off. When you reach your desired consistency, let it cool and pour into a container to refrigerate.
To make raspberry sauce, combine raspberries, 1-1/2 tablespoons of sugar substitute and ½ teaspoon of lemon juice to a boil. Let thicken and cool slightly. Press mixture through a fine strainer. This will take patience and about 20 minutes of mashing, but you will be rewarded with a rich, seedless sauce. Discard seeds.
For each fool: Put 2 tablespoons of cooked strawberries at the bottom of a cocktail glass. Whip the cream with the remaining sweetener. Put 2 tablespoons of whipped cream in each glass. Add 1 tablespoon of the seedless raspberry sauce. Top with more whipped cream. Garnish with whole berries.