Preheat your oven to 170°C (340°F). Line a baking tray with parchment paper or use silicone bar moulds.
In a large bowl, combine peanuts, cashews, almonds, and puffed rice.
In a small microwave-safe bowl, heat the brown rice syrup for 30 seconds. Stir in vanilla extract and sea salt.
Pour the syrup mixture over the nuts and rice, and mix until everything is evenly coated.
Transfer the mixture to your prepared tray or molds, pressing it down firmly into an even layer.
Bake for 18–20 minutes until golden and lightly crisp.
Remove from oven and let cool for at least 30 minutes to set.
Once cooled, melt dark chocolate and coconut oil in the microwave (30-second bursts, stirring in between).
Dip the bottom of each bar into the melted chocolate and drizzle more on top.
Finish with a sprinkle of flaky sea salt and chill until set.