Filling: Mix coconut milk, finely shredded coconut, stevia, and salt. Refrigerate 1 hour so that it's easier to make bars.
Make bars and place in freezer 1 hour to overnight.
Coating: Mix cacao powder, coconut oil, stevia, and vanilla extract.* Take bars out of the freezer and one by one place in coating. Place each bar on parchment paper and freeze. Store in the fridge or freezer.
Notes
* The coating just coats all the bars. If you use even a bit more chocolate on each you'll need more than the recipe calls for. In that case you could use 1 cup cacao powder, 1 cup coconut oil, 40 drops stevia, and 2 teaspoons vanilla.