Place frozen raspberries in small, nonstick pot over medium-low heat, cover, and bring to slow simmer, stirring occasionally (approx 10 min)
Add sugar and half pinch of salt and continue to stir another 2 minutes
Strain berries through fine-mesh strainer into bowl using rubber spatula
Cover and refrigerate at least 2 hours, up to 3 days.
Stir in lemon juice before serving
==Panna Cotta==
Pour milk in to medium sauce pan, and sprinkle surface evenly with gelatin.
Let stand for 10 minutes to hydrate the gelatin.
Note, do not trust the measurement on the gelatin packaging: measure it yourself to be exact!
Meanwhile turn contents of two ice cube trays into large metal bowl and add 4 cups cold water
Measure cream into large cup and stir in vanilla
Set aside 4 individual ramekins on baking sheet
Heat milk and gelatin mixture over high heat, stirring constantly until gelatin is dissolved and mixture reaches 135 degrees on instant-read thermometer (about 1.5 minutes)
Remove from heat and add sugar, salt, and stir until dissolved (about 1 minute)
Transfer milk mixture to a second small pot
Slowly pour in cream mixture into small pot with milk
Hold small pot in ice bath and stir until temperature drops to 50 degrees, with the consistency of eggnog mixture (about 10 minutes)
Distribute evenly into 4 ramekins
Cover with plastic wrap, refrigerate approx 4 hours
==Plate==
Bring small pot of water to a simmer
Hold bottom of ramekin in the hot water for about 3 seconds
Carefully run the tip of a paring knife around the inside edge of the ramekin to separate the panna cotta from the sides
Return the ramekin to the hot water for another 3 seconds.
Not too long or youall get a runny surface
Put a small plat over the ramekin and grasping the plate and ramekin with both hands, flip it over with a sharp downward motion to force the panna cotta to fall onto the plate.
This way, you should be able to safely lift up the ramekin and the panna cotta will be separated.
Spoon a few teaspoons of raspberry sauce on a serving plate
Carefully transfer the panna cotta on top of the raspberry sauce, garnish with mint and/or fresh raspberries, and serve immediately
==To use real vanilla beans instead of extract==
Use paring knife to scrape vanilla seeds into cream (instead of extract), and place pod in the cream along with seeds
After mixture cooled to 50 degrees, strain out the seeds and pod.
==To make a day ahead (I didn't try it yet)==
Decrease gelatin to 1 5/16 t
Filled ramekins can be chilled for 18-24 hours with the reduced gelatin
==Garnish==
The panna cotta should support fruit or nuts.
One raspberry in the center of the ramekin would make a nice garnish (I didn't try it yet)