Prep the pan. Line an 8x8-inch pan with parchment paper, leaving overhang on two sides for easy lifting.
Lightly grease the paper if your mixture tends to stick.
Toast the coconut (optional but recommended). In a dry skillet over medium heat, toast the shredded coconut for 3–5 minutes, stirring often, until lightly golden and fragrant. Let it cool. This step adds a deeper, nuttier flavor.
Mix dry ingredients. In a large bowl, stir together 1 1/2 cups shredded coconut, 1 cup rolled oats, and 1/2 to 3/4 cup protein powder.
Add a pinch of salt. If using seeds or flax meal, mix them in now.
Warm the binders. In a small saucepan or microwave-safe bowl, gently warm 1/2 cup nut or seed butter, 1/3 cup honey or maple syrup, and 3 tablespoons melted coconut oil until smooth and pourable. Stir in 1 teaspoon vanilla extract.
Combine. Pour the warm mixture over the dry ingredients.
Stir with a sturdy spoon until everything is evenly coated and clumps together when pressed. If it’s too dry, add 1–2 teaspoons more coconut oil or a splash of milk. If it’s too wet, sprinkle in extra oats or protein powder.
Fold in extras. Add 2–4 tablespoons of your chosen add-ins, like mini chocolate chips or chopped nuts.
Stir just to distribute.
Press firmly. Transfer the mixture to the lined pan. Use the back of a spatula or a sheet of parchment to press it down very firmly into an even layer, getting into the corners. Firm pressure is key for bars that hold together.
Chill to set. Refrigerate for at least 2 hours, or freeze for 30–40 minutes, until solid.
Slice. Lift the slab out with the parchment and cut into 12 bars or 16 squares using a sharp knife. Wipe the blade between cuts for clean edges.
Optional finish. Drizzle melted dark chocolate over the top and let it set in the fridge for 10 minutes.