In a small saucepan, sprinkle gelatin over milk; let stand 1 minute. Cook over low heat, stirring until gelatin dissolves (do not boil). Set aside to cool.
In a food processor, puree 1 ½ pints strawberries, stopping occasionally to scrape down sides of bowl. Press strawberries through a fine wire-mesh strainer into a bowl, discarding solids.
Stir cooled milk mixture into strawberry puree. Add Splenda Sweetener and vanilla extract, stirring until sweetener dissolves.
Coat four (6-ounce) ramekins with cooking spray. Divide strawberry mixture among ramekins. Cover ramekins with plastic wrap; refrigerate 4 hours or overnight until set.
Run a knife around the edge of each ramekin and unmold onto serving plates. Serve with sliced strawberries.