Preheat the oven to 175 C. Spread the pecans out on an ungreased baking tray. Bake for 5 to 7 minutes until they're fragrant and lightly toasted. Set aside to cool for 15 minutes, then use your fingers to break them into small pieces, or chop them up coarsely. Reserve 1/3 cup to sprinkle on top of the bars at the end.
Now in a mixing bowl, combine the oats, coconut and cocoa. Add the toasted pecan pieces (not the reserved 1/3 cup) and stir well to combine.
Add the nut butter (if it's very thick, or cold from the fridge, microwave it to melt it a little bit so you can mix it in easily) and stir it into the dry ingredients. Add the oil, honey and vanilla and stir the whole mixture together until it's all evenly coated. It will look quite wet (see photos below) but if it feels excessively wet, add a couple of tablespoons of oats. If it seems dry, add more honey or nut butter.
Tip the mixture into an 8-inch square baking pan, lined with non-stick baking paper with an overhang for easy removal. Press the mixture down firmly and evenly with your fingers or the base of a measuring cup. It's important to tightly pack it in so the bars hold together when you cut them.
Bake for 25 to 30 minutes until the edges are set and darkened. The center will still feel soft. Immediately scatter the finely chopped chocolate all over the top. Wait for a few seconds to let it melt, then use a spoon or blunt knife to spread it all over in an even layer. Scatter the remaining toasted pecans on top and press them in lightly to help them stick.
Allow the granola to cool at room temperature for 30 minutes, then refrigerate for 1 hour to let the chocolate set. Use the paper overhang to remove it from the pan, then slice into 12 equal bars using a very sharp knife. There might be some crumbly bits at the edge (honestly the best pieces if you ask me!) but the bars will hold together well.
Store in the fridge for about two weeks, and they can also be frozen for longer. Happy snacking!