In a small bowl, sprinkle the gelatin over the room temperature skim milk. Let it sit for about 5 minutes to bloom.
In a medium saucepan, combine the heavy whipping cream, sugar, and vanilla extract. Heat over medium heat, whisking occasionally, until hot but not boiling.
Remove the cream mixture from heat. Stir in the bloomed gelatin mixture until completely dissolved.
Divide the panna cotta mixture among serving cups or molds. Let cool to room temperature before refrigerating.
Refrigerate for at least 4 hours, or until fully set. For best results, chill overnight.
Prepare the raspberry sauce by combining fresh raspberries, 1 cup of sugar, and lemon juice in a saucepan. Cook over medium heat until thickened.
Blend the raspberry sauce until smooth and strain through a sieve to remove seeds, if desired. Allow to cool.
Once set, gently remove panna cotta from molds and drizzle with raspberry sauce. Garnish with fresh berries before serving.
