• Preheat oven to 425℉. Spray muffin tin with baking spray or line with muffin papers. Rinse 2 cups blueberries with cold water and drain in colander.

Prepare the Batter

• In a large bowl, mix together 2 cups all-purpose flour, 1/2 cup granulated sugar, 1 teaspoon baking soda, 1 teaspoon salt, and 1 teaspoon ground cinnamon.
• Place 1 cup sourdough starter in another bowl along with 1/2 cup whole milk, 1/4 cup vegetable oil, and 1 large egg. Mix together with a fork or dough whisk to combine. Blend the sourdough into the flour mixture, until thoroughly combined.
• Gently fold in the fresh or frozen blueberries just until blended.
Try not to overmix the muffin batter to avoid coneheads that might develop during baking, or a tough crumb.

Bake the Muffins

• Spoon batter into the prepared muffin cups, filling two-thirds full. If desired, sprinkle with 3 teaspoons decorating sugar or demerara sugar. 
• Bake in preheated oven for 15-20 minutes, until lightly browned. Remove from oven and allow to set for 5 minutes before placing on a wire rack to cool completely.
• Serve with butter or honey butter for brunch or a morning snack.
• Store in a covered container for up to 3 days, or freeze in a plastic freezer bag for up to 2 months. This recipe will serve 10-12 people.