Preheat oven to 300°F (150°C) and line a baking sheet with parchment paper.
Mix oats, almonds, ground flax, and salt in a large bowl. Add lemon zest, coconut oil, maple syrup, vanilla, and almond extract; stir until evenly coated.
Transfer mixture to baking sheet, press down firmly into an even layer, and bake for 30 minutes without stirring.
Let granola cool completely (about 1 hour), then sprinkle with dried blueberries and break into clusters.
Enjoy immediately or store in an airtight container at room temperature for up to 3 weeks.
Notes
For bigger clusters, pack the mixture tightly before baking and avoid stirring during baking.