01 - Line an 8x8-inch baking pan with parchment paper, leaving enough overhang on the sides to easily lift the treats out later.
02 - In a large mixing bowl, whisk together the rolled oats, shredded coconut, chopped hazelnuts, chia seeds, cocoa powder, and sea salt until evenly distributed.
03 - In a small saucepan over low heat, gently warm the nut butter and maple syrup, stirring constantly until smooth and pourable. Remove from heat and stir in the vanilla extract.
04 - Pour the warm wet mixture over the dry ingredients. Using a spatula, fold and stir thoroughly until every oat and seed is coated and the mixture holds together when pressed.
05 - Transfer the mixture to the prepared pan. Using the back of a spatula or your hands, press firmly into a compact, even layer. Sprinkle the extra chopped hazelnuts and shredded coconut on top, pressing lightly so they adhere.
06 - Cover the pan with plastic wrap and refrigerate for at least 30 minutes, or until the mixture is completely set and firm to the touch.
07 - Lift the slab out of the pan using the parchment overhang. Place on a cutting board and cut into 16 even squares. Store in an airtight container in the refrigerator for up to 1 week.