In a medium bowl, sprinkle the gelatin over the milk and let stand for 5 minutes.
In a saucepan over medium heat, combine the cream and sugar. Cook, stirring to dissolve the sugar, until small bubbles appear around the outside of the pan.
Slowly add the cream mixture to the gelatin mixture. Stir until smooth. Whisk in vanilla.
Spray 8 ramekins with cooking spray. Divide the mixture evenly among ramekins. Cover and refrigerate 6 hours or overnight.
Fill a small bowl with very warm water. Dip the bottom of the ramekins in the water for about 10 seconds. Run a knife around edges of custard to loosen. Invert onto dessert plates.
Spoon berries around the panna cotta and serve immediately.