Preheat oven to 300°F (150°C) and line a sheet pan with parchment paper.

Process 1 cup oats into flour, then combine with remaining 3 cups oats, chia seeds, cinnamon, and salt in a large bowl.

Melt 1/2 cup coconut oil, then stir in 1/2 cup brown sugar, 2 Tablespoons maple syrup, and 1 Tablespoon vanilla extract.

Pour the wet mixture over the oat mixture, stirring until evenly coated. Spread onto the prepared pan and press firmly.

Bake for 25-30 minutes until light golden brown, rotating halfway through without stirring.

Let cool slightly, then sprinkle with 2/3 - 1 cup chocolate chips to melt. Cool completely before breaking into clusters. Store in an airtight container.