Wash raspberries and dry completely using paper towels. Moisture will cause chocolate to seize.
In a bowl, mash raspberries until thick but slightly textured.
Stir in powdered sugar and vanilla if using.
Line a tray with parchment paper. Spoon 1 tablespoon portions onto the tray.
Freeze for 30–45 minutes until firm.
Melt chocolate in microwave in 20-second intervals, stirring between each round until smooth.
Remove raspberry centers from freezer and dip into melted chocolate using a fork.
Tap off excess chocolate and return to tray.
Sprinkle sea salt on top before chocolate sets if desired.
Refrigerate 15–20 minutes until fully set.