1. Preheat the oven to 375 degrees Fahrenheit. Lightly spray or grease a 12-cup muffin tin.
2. In a bowl, pour half a cup hot water over the raisins. Let stand for 10 minutes.
3. In a separate bowl, stir together the milk and lemon juice; let stand for five minutes. Stir in the bran and wheat germ; let stand for five minutes.
4. In a third bowl, whisk together the flour, baking powder, baking soda, cinnamon and salt; set aside.
5. Whisk the brown sugar, oil, molasses, eggs and vanilla into the soured milk/bran mixture until well combined. Drain the raisins, stir into the wet mixture.
6. Pour the wet mixture over the flour mixture and gently stir the two mixtures together.
7. Divide the batter evenly among the prepared muffin cups. Evenly sprinkle the sunflower and flax seeds over the batter.
8. Bake in the center of the preheated oven until the tops spring back when lightly pressed, 20–23 minutes. Cool the muffins in the pan on a wire rack for 10 minutes. Remove the muffins from the pan, transferring to a wire rack to cool completely.