Preheat oven to 275°F (135°C).

In a large bowl, combine toasted whole grain cereal, old fashioned oats, walnuts, almonds, and hazelnuts.

In a small saucepan, bring honey and vegetable oil just to a boil.

Drizzle the honey-oil mixture over the cereal mixture and toss to coat evenly.

Spread the granola mixture onto a large rimmed baking sheet.

Bake for 1 hour and 30 minutes, stirring every 15 minutes, until golden brown and dry.

Scatter dried blueberries, dried sweetened cranberries, and golden raisins over the granola.

Sprinkle ground cinnamon over the granola and toss to incorporate evenly.

Cool the granola completely in the pan on a rack, stirring occasionally to prevent clumping.

Store airtight at room temperature for up to 2 weeks.