Mix the chopped mixed nuts, oat flakes, nut/seed butter, coconut oil, maple syrup, chia seeds, vanilla extract, and salt in a bowl until well combined.
Press the mixture into a 10x6 inch baking tray lined with parchment paper.
Melt the dark chocolate and pour it over the granola base, spreading it evenly.
Sprinkle a pinch of sea salt on top.
Freeze for 15 minutes to set the chocolate.
Cut into bars and enjoy!
