• 1 package (1/4 ounce) active dry yeast
• 2 1/4 cups warm water
• 6 cups all-purpose flour
• 1 cup light brown sugar
• 1 teaspoon salt
• 1/2 teaspoon ground cinnamon
• 1 large egg
• 6 tablespoons unsalted butter room temperature
• vegetable oil for greasing
• 2 pints (5 or 6 cups) blueberries

In a small bowl, mix yeast and water; set aside until foamy, about 5 minutes. In a large bowl, combine flour, 1/2 cup brown sugar, salt, and cinnamon. Stir egg into yeast; pour into flour mixture and mix on low speed. Add butter, and mix until combined. Knead dough until smooth and pliable but still relatively wet, about 5 minutes on a stand mixer.

Grease a large bowl and 2 baking sheets with oil; set baking sheets aside. Scrape dough into bowl and cover with plastic wrap. Let rise in a warm place until doubled, about 1 hour.

Preheat oven to 400°. Halve dough, and place 1 piece on each baking sheet. Stretch out slightly, until dough forms a 1-inch-thick oval; cover with greased plastic wrap. Let rise again about 1 hour.

With greased fingers, dimple surface of loaf; sprinkle each with 1 pint berries and 1/4 cup brown sugar each. Bake until golden brown, 30 to 35 minutes, rotating once. Slice and serve warm.