Preheat the oven to 350 degrees. Line an 8x8 baking pan with parchment paper and grease with coconut oil or cooking spray. Set aside.
Place the walnuts, 1 cup of the oats and the coconut in the food processor. Process for 30 seconds or until finely ground.
Remove processor bowl and dump ground walnuts, oats and coconut in a big bowl. Stir in remaining 1/2 cup of oats and all of the other seeds (flax, hemp, pumpkin and sunflower), cinnamon (or cardamom) and salt and toss to combine.
In a glass measuring cup or small bowl, stir together melted coconut oil, maple syrup and vanilla and stir well to incorporate. Pour liquid onto the nut and seed mixture and, using a spatula or your hands, mix everything together and coat thoroughly.
Carefully dump the nut and seed mixture into the prepared baking pan and use your fingers, an offset spatula or the bottom of a measuring cup to press it down evenly. Alternatively, you can top the mixture with a piece of parchment paper and press down thoroughly with your hands or back of measuring cup or glass. When you think it is well-pressed, press again so the ingredients really stick together well.
Bake for 25 minutes, or until the edges are golden. Let cool completely before cutting into 12 bars. Reserve any remaining granola bar crumbs and sprinkle on yogurt. Store bars in an air-tight container and refrigerate.