In a small bowl, combine 1 1/2 cups Warm water (about 110°F) with 2 ¼ teaspoons Instant yeast and 1 tablespoon Brown sugar Let it sit for 5–10 minutes until it becomes foamy.
In a large mixing bowl, whisk together 2 cups All-purpose flour, 1 cup Whole wheat flour, 1/2 cup Rolled oats 2 tablespoons Sunflower seeds, 2 tablespoons Flaxseeds, and 1 ½ teaspoons Salt.
Add the foamy yeast mixture and 2 tablespoons olive oil to the dry ingredients. Stir until a rough dough forms.
Turn the dough onto a floured surface and knead for 8–10 minutes until smooth and elastic. Alternatively, use a stand mixer with a dough hook for 6–7 minutes.
Place the dough in a greased bowl, cover with a clean towel, and let it rise in a warm spot for 1–1.5 hours, or until it doubles in size.
Punch down the risen dough and shape it into a loaf. Place it into a greased 9x5-inch loaf pan.
Cover the loaf and let it rise again for 30–45 minutes, until it puffs up slightly above the pan edges.
Preheat your oven to 375°F (190°C). Bake the bread for 30–35 minutes, or until the top is golden brown and it sounds hollow when tapped.
Remove the bread from the pan and let it cool on a wire rack for at least 20 minutes before slicing. Enjoy warm with butter, jam, or your favorite spreads!