Preparation Preheat oven to 200°F. Line a 9x5" loaf pan with parchment paper, leaving a generous overhang on both long sides. Coat with nonstick spray. Grind 1/2 cup flaxseed in spice mill to a fine powder. Whisk eggs, oil, and tahini in a large bowl to combine. Add ground flaxseed, black and white sesame seeds, poppy seeds, salt, and remaining 1/2 cup flaxseed and mix well. Let sit 30 minutes to let flax hydrate. Scrape batter into prepared pan and bake until top is firm to the touch (an instant-read thermometer inserted into the center should register 165°F), 1 1/2–2 hours. Transfer pan to a wire rack and let loaf cool in pan 5 minutes. Using parchment overhang, lift loaf out of pan and onto rack; remove parchment. Let loaf cool completely. Do Ahead Loaf can be made 5 days ahead. Wrap tightly and chill.
Preparation Preheat oven to 200°F. Line a 9x5" loaf pan with parchment paper, leaving a generous overhang on both long sides. Coat with nonstick spray. Grind 1/2 cup flaxseed in spice mill to a fine powder. Whisk eggs, oil, and tahini in a large bowl to combine. Add ground flaxseed, black and white sesame seeds, poppy seeds, salt, and remaining 1/2 cup flaxseed and mix well. Let sit 30 minutes to let flax hydrate. Scrape batter into prepared pan and bake until top is firm to the touch (an instant-read thermometer inserted into the center should register 165°F), 1 1/2–2 hours. Transfer pan to a wire rack and let loaf cool in pan 5 minutes. Using parchment overhang, lift loaf out of pan and onto rack; remove parchment. Let loaf cool completely. Do Ahead Loaf can be made 5 days ahead. Wrap tightly and chill.