Prepare a nine inch square baking pan by lining it with aluminum foil, dull side up. Give the foil a light coating of non-stick cooking spray and set aside.
In a large bowl, combine the rolled oats, chopped almonds, chopped cranberries, coconut, pepitas, and flax seed and stir well to evenly mix it all up.
In a small saucepan set over medium heat, combine the sugar, honey, and butter. Cook, stirring occasionally, until the butter melts and the mixture starts to bubble. Once it has come to a light boil, cook the mixture for one to two minutes to dissolve the sugar. Remove the pot from the heat and stir in the vanilla and kosher salt. Pour this over the oat mixture and stir very well to combine.
Scrape the mixture into your prepared pan and press it down into an even layer. To do this, I like to use a piece of parchment paper to lay over the top of the granola bar mixture and press firmly with my hands of a second nine inch square pan. Scatter the top of the granola bars with the finely chopped dark chocolate and give it another good press.
Cover the pan with parchment paper and pop it in the fridge for two hours to firm up. Carefully lift the granola bars out of the pan and slice into 12 equal bars. Wrap each in parchment, wax paper, or plastic wrap and you’re good to go!
For a chewier bar, store the bars in the fridge or a cooler. For softer bars, they store well in the cupboard or in a backpack.