Mix all dry ingredients (oats, salt, blueberries and pepitas) together in a large mixing bowl.
In a separate mixing bowl, mix together honey, sun butter and vanilla until well incorporated. Pour the wet ingredients onto the dry ingredients and mix thoroughly with a spoon or spatula. The mixture will be thick and sticky, and it should take several minutes to mix it together by hand. Make sure all the oats are well covered.
Line an 8x10 or 8x8 baking pan with parchment paper. Pour the mixture into the pan and press down hard to form the mixture into bars. Use the back of a measuring cup or clean hands with a light coat of olive oil to push down on the mixture. You want to compact the bars as much as possible.
Put the pan in the refrigerator and let the bars cool for at least an hour. After the bars are fully cooled, remove them from the pan and cut into individual serving sizes.
Notes
Ingredient Notes: Use old-fashioned or quick-cooking oats in this recipe, but not steel-cut oats.Substitutions: If you don't need these granola bars to be nut-free, you can substitute peanut butter or almond butter for the sunflower butter.Storage: Make sure to store these bars in the refrigerator or freezer to keep their shape. If they are stored at room temperature, they will crumble and fall apart. Separate the stored bars with wax paper to keep them from sticking together.