Melt the dark and milk chocolate in a double boiler, stirring until smooth.

Remove from heat and stir in the heavy cream, vanilla extract, and sea salt until well combined.

Pour the chocolate mixture into heart-shaped molds, filling each cavity halfway.

Refrigerate for about 15 minutes until slightly set.

Fill the molds to the top with more chocolate mixture and smooth the surface.

Chill in the refrigerator for at least 30 minutes until fully set.

Melt the white chocolate and drizzle over the set chocolates.

Sprinkle with decorative sprinkles if desired.

Carefully remove the chocolates from the molds.