Preheat your oven to 350°F (175°C). Line a 9x5-inch loaf pan with parchment paper, leaving an overhang on the long sides.
In a large bowl, combine the sunflower seeds, pumpkin seeds, ground flaxseed, chia seeds, psyllium husk powder, almond flour, baking powder, and salt. Stir until all the seeds and dry ingredients are evenly mixed.
In a separate bowl, whisk together the eggs, melted coconut oil, and apple cider vinegar. Pour the wet mixture into the dry ingredients and stir well.Add the warm water and mix thoroughly until a thick, seedy dough comes together. Let the dough rest for 5 minutes so the chia seeds and psyllium husk absorb the liquid and the dough thickens.
Transfer the dough into the prepared loaf pan, pressing it firmly and evenly into all corners. Smooth the top with the back of a wet spoon.
Bake for 50 to 60 minutes, until the top is firm and golden and the loaf sounds hollow when tapped. The edges should pull slightly away from the pan.
Remove from the oven and let the bread cool in the pan for 15 minutes. Then lift it out using the parchment and transfer to a wire rack.
Let the bread cool completely before slicing, ideally 1 to 2 hours. This bread has an incredible nutty, seedy flavor and dense hearty texture. It is fantastic toasted and topped with butter, avocado, or cream cheese.