Preheat oven to 375 degrees F (190 degrees C). Grease 24 muffin cups or line with paper liners.
Sift flour, white sugar, baking powder, salt, and baking soda together in a large bowl; add oats and chia seeds.
Mix orange juice, applesauce, oil, and eggs together in a bowl; stir into flour mixture until batter is just combined. Fold blueberries into batter. Spoon batter into prepared muffin cups, filling 3/4-full.
Mix brown sugar and cinnamon together in a bowl; sprinkle over batter.
Bake in the preheated oven until a toothpick inserted in the center of a muffin comes out clean, 18 to 20 minutes.
