Step 1: Preheat the oven

• Preheat your oven to 375°F (190°C). Line a 12-cup muffin tin with paper liners or grease the cups well.

Step 2: Mix the dry ingredients

• In a large bowl, whisk together the whole wheat flour, all-purpose flour, wheat bran, baking powder, baking soda, and salt.

Step 3: Combine the wet ingredients

• In a separate bowl, whisk together the buttermilk, eggs, vegetable oil, brown sugar, and vanilla extract until smooth.

Step 4: Make the batter

• Gradually add the wet ingredients to the dry ingredients, mixing gently until just combined. Do not overmix.

Step 5: Fold in the blueberries

• Gently fold the blueberries into the batter, being careful not to crush them.

Step 6: Fill the muffin tin

• Divide the batter evenly among the prepared muffin cups, filling each about 3/4 full.

Step 7: Bake the muffins

• Bake for 20–25 minutes, or until a toothpick inserted into the center of a muffin comes out clean.

Step 8: Cool and serve

• Allow the muffins to cool in the tin for 5 minutes, then transfer to a wire rack to cool completely. Serve warm or at room temperature.