Prepare Oven and Dry Mix: Preheat oven to 300°F (150°C). Line a baking sheet with parchment. In a medium bowl, combine oats, walnuts, coconut flakes, flaxseed, cinnamon, cardamom, and salt; stir well.
Combine Wet Ingredients: In a small bowl, whisk olive oil, maple syrup, almond butter, and orange zest until smooth and emulsified.
Combine and Form: Pour the wet mixture over the dry and fold until fully coated. Transfer to the prepared sheet and press firmly into a compact, even layer about ¼ inch (0.5–1 cm) thick.
Bake in Two Stages: Bake 15 minutes. Remove and gently break into a few large pieces. Return to the oven and bake 15–20 minutes more, until fragrant, light golden-brown, and dry to the touch with crisp edges.
Cool for Crunch: Cool completely on the sheet 25–30 minutes without touching. Break into desired cluster size and store airtight.