Chop the dates into small pieces using a sharp knife, or soak them briefly in warm water if they seem too dry, then drain well.
Place the chopped dates into a food processor and add a pinch of sea salt and vanilla extract. Pulse until the mixture becomes sticky and begins to clump together, about 30 seconds.
In a microwave-safe bowl, melt the dark chocolate in 20-second bursts, stirring well after each, until smooth and glossy. Allow to cool slightly.
Pour the melted chocolate into the food processor with the date mixture and pulse until thoroughly combined and sticky.
Add the chopped nuts or seeds to the mixture and pulse a few more times to distribute evenly, making sure the mixture holds together when pressed.
Line a baking sheet with parchment paper. Using a tablespoon or small scoop, portion out the mixture and roll into small balls or press into tiny bars, about 1 inch in diameter.
Place the bites on the prepared sheet and refrigerate for at least 30 minutes until firm and shiny. For quicker setting, freeze for 15 minutes.
If desired, melt a little extra chocolate and drizzle over the bites for decoration, then sprinkle with sea salt or crushed nuts for an added touch of flavor.
Once set, transfer the bites to an airtight container and store in the fridge for up to a week or freeze for longer storage. Let sit at room temperature a few minutes before serving to soften slightly.
