Preheat oven to 400 degrees F (200 degrees C).

Line a 12-cup muffin tin with muffin liners.

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

In another large bowl, whisk together the brown sugar, eggs, and milk.

Whisk in the pumpkin puree until smooth.

Create a well in the center of the dry ingredients.

Pour the wet ingredients into the well and mix until just moistened.

Let the batter stand for 5 minutes to allow the bran to soak up moisture.

Gently fold in the blueberries and raspberries.

Spoon the batter into the prepared muffin cups.

Bake for 10 minutes at 400 degrees F (200 degrees C).

Reduce oven temperature to 350 degrees F (175 degrees C) and bake for another 15-20 minutes, or until a toothpick inserted into the center comes out clean.

Cool the muffins in the tin for a few minutes before transferring them to a wire rack to cool completely.

Serve and enjoy!