Preheat oven to 275 degrees F.
Line large baking sheet(s) with parchment paper or oil lightly. Place oats in a large bowl and set aside.
Add nuts and seeds to the oats in the bowl.
Put brown sugar and water in a microwave-safe bowl or in a saucepan on low and heat until sugar dissolves (about 1 minute or less).
Add vanilla and salt to the melted sugar mixture. Pour over oat-nut mixture in the large bowl and stir well.
Spread granola mixture evenly on the prepared pan(s). Bake 15–20 minutes.
Remove from oven. Sprinkle dried fruit and honey (if using) on top while still warm. Cool before storing.