Combine sweetener and cornstarch in a small saucepan. Stir in orange juice. Bring to a boil; cook, stirring constantly, 1 minute or until mixture is thickened and bubbly. Remove from heat, and stir in extract. Cool completely.
Combine orange juice mixture and strawberries in a bowl; stir gently. Cover and chill 30 minutes.
To serve, spoon sauce over dessert shells.
Tip: This luscious sauce is also good spooned over no-sugar-added ice cream, angel food cake, or fat-free pound cake.