Anadama Bread

Ingredients

• 2 tablespoons unsalted butter, room temperature, plus more
• 1 1/4-ounce envelope active dry yeast (about 2 1/4 teaspoon)
• 1 cup stone-ground medium cornmeal
• 1/4 cup mild-flavored (light) molasses
• 2 tablespoons hemp seeds or white sesame seeds
• 1 tablespoon nigella seeds or black sesame seeds
• 2 teaspoons golden flaxseed
• 2 teaspoons brown flaxseed
• 2 teaspoons poppy seeds
• 1 1/4 teaspoon kosher salt
• 2 cups all-purpose flour, plus more for surface
• 1 large egg, beaten to blend
• Salted butter (for serving)