Line a baking sheet with parchment paper.
In a small skillet, toast the fennel seeds over moderate heat until fragrant, about 2 minutes.
Add the sugar and cook, stirring frequently, until the sugar is melted and coats the seeds, about 15 seconds.
Scrape the candied fennel seeds onto a plate and let cool.
Crumble any clumps to separate the seeds.2.
Put the chocolate into a microwave-safe bowl and microwave in 30-second bursts until almost melted.
Stir the chocolate until completely melted and an instant-read thermometer inserted in it registers 90°F.
3. Working very quickly, dip a crispbread in the chocolate and use an offset spatula to spread the chocolate in a very thin layer so it completely coats the crispbread.
Transfer to the prepared baking sheet and sprinkle with some of the fennel seeds, ginger and sea salt.
Repeat with the remaining crispbreads, chocolate and toppings.
Refrigerate the chocolate-covered crispbreads until just set, about 5 minutes, then serve.
Make ahead: The chocolate-covered crispbreads can be stored in an airtight container at room temperature for up to 5 days.