Line your square pan with parchment paper, making sure the edges hang over for easy removal.
In a large bowl, combine the sunflower seeds, chia seeds, rolled oats, sesame seeds, and coconut flakes. Toss everything together until evenly mixed.
Warm the honey and melted coconut oil in a small saucepan over low heat, just until combined and slightly bubbling, about 2 minutes. The aroma should be sweet and nutty.
Pour the warm honey mixture over the seed and oat mixture. Use a spatula to gently fold everything together, coating all the ingredients evenly with the sticky mixture. It will become thick and slightly glossy.
Transfer the mixture into your prepared pan. Press it down firmly with the back of a spatula or your damp hands, ensuring the mixture is compacted into an even layer. This helps create clean bars later.
Place the pan in the fridge and chill for at least 2 hours, or until the mixture is fully firm and set. You'll hear a satisfying crunch as the mixture solidifies.
Once set, lift the entire block out of the pan using the parchment edges, and transfer it to a cutting board.
Using a sharp knife, cut the mixture into squares or rectangles. Wipe the blade clean between cuts to keep the edges neat.
Arrange the bars on a plate or store in an airtight container in the fridge. They will keep fresh for about a week, and the natural flavors will deepen over time.
Enjoy your homemade no bake seed bars as a wholesome snack or quick breakfast on busy mornings.