Whole Wheat Sweet Potato Challah

INGREDIENTS

• ¾ cup water
• 2½ teaspoons instant yeast
• 1 tablespoons + ¼ cup sugar
• ¼ cup sunflower oil
• 2 eggs
• ½ tablespoon salt
• 1 cup sweet potato puree
• 2 cups whole wheat pastry flour
• 2+ cups unbleached all purpose flour
• Topping:
• 1 egg
• poppy or sesame seeds