Preheat oven to 325 degrees F. Line a baking pan with parchment paper.
In a large mixing bowl, mix together oats, pistachios, Grape-Nuts, dried cranberries, sunflower seeds, cinnamon, and salt.
In a small pan, cook brown sugar and apple juice over medium-high heat until sugar dissolves (2-3 minutes). Mix in the vanilla and then pour over the dry ingredients and mix until everything is moist.
Spread granola evenly onto the parchment lined baking pan and bake for 20-25 minutes until golden, stirring halfway through.
Let granola cool completely on the baking sheet before storing in an airtight container.