Heat oven to 350˚F with rack set in middle position. Coat a 8½ × 4½-inch loaf pan with nonstick spray. Line pan with parchment paper, leaving a 2-inch overhang on two sides.

Arrange sunflower seeds and almonds in a single layer on a baking sheet; transfer to oven and roast until seeds and almonds are lightly toasted, golden and fragrant, 8–10 minutes. Transfer toasted seeds and almonds to a large bowl with almond flour, hemp hearts, pumpkin seeds, flax seeds, psyllium husk, chia seeds, salt and pepper; toss to thoroughly combine.

Whisk together water, oil, and maple syrup in a liquid measuring cup; pour water mixture over seed and nut mixture and stir until mixture is thoroughly combined and a thick cohesive dough comes together. Scoop dough into prepared loaf pan. Press dough down to fill pan then smooth top into an even layer. Bake bread until top is golden brown and center has slightly puffed, 45 minutes.

Line a small baking sheet with parchment paper.

Remove pan from oven and lift bread out of pan by pulling up on the parchment paper. Flip loaf over and place, bottom facing up, on parchment lined baking sheet. Return bread to oven and bake until top and edges are golden brown, 20 more minutes.

Remove from oven, flip loaf back over and let cool completely.

To serve, toast slices on a baking sheet under a broiler (or in a toaster oven) until golden brown, 3–4 minutes per side. Top slices as desired.