In the bowl of a stand mixer fitted with the paddle attachment, stir together sprouted wheat flour, 1 cup (127g) bread flour, yeast, and salt by hand. Add honey and melted butter. Add warm water, and beat at low speed until dough comes together. Cover and let stand for 30 minutes.
In a small bowl, stir together 1/4 cup (36g) pumpkin seeds, 1 tablespoon (9g) flax seeds, 1 tablespoon (9g) sesame seeds, and 1 tablespoon (9g) poppy seeds. Stir in 3 tablespoons (45g) water, and let soak for 30 minutes.
Add seed mixture and remaining 1/4 cup (32g) bread flour to sprouted wheat flour mixture. Switch to the dough hook attachment. Beat at low speed until dough is smooth and elastic, about 8 minutes. Check for proper gluten development using the windowpane test. (See Note.)
Lightly oil a large bowl. Shape dough into a smooth ball, and place in bowl, turning to grease top. Cover and let rise in a warm, draft-free place (75°F/24°C) until doubled in size, about 45 minutes. (See Note.)
Spray an 8½x4½-inch loaf pan with cooking spray.
Lightly pat dough into an 8x7-inch oval, and place horizontally in front of you. Starting with top edge, fold top third of dough to center, pressing to seal. Fold bottom third over folded portion, pressing to seal. Fold dough in half lengthwise so long edges meet. Using the heel of your hand, firmly press edges to seal. Place seam side down in prepared pan. Cover and let rise in a warm, draft-free place (75°F/24°C) until doubled in size, 30 to 45 minutes.
Preheat oven to 375°F (190°C).
Gently brush remaining 1 tablespoon (15g) water on top of loaf. Sprinkle with remaining 1 tablespoon (9g) pumpkin seeds. Sprinkle with remaining 1 1/2 teaspoons (4.5g) flax seeds, remaining 1 1/2 teaspoons (4.5g) sesame seeds, and remaining 1 1/2 teaspoons (4.5g) poppy seeds. Using a lame or razor blade, score top of loaf with two diagonal cuts.
Bake until an instant-read thermometer inserted in center registers 205°F (96°C), 30 to 35 minutes. Let cool in pan for 15 minutes. Remove from pan, and let cool completely on a wire rack.