Pour 1 cup of hot water over the raisins and let them sit for 15 minutes to plump. Strain the water out. Divide into two equal portions.
In a food processor or blender, combine the applesauce, sugar, molasses, oil, eggs, vanilla extract, and half of the drained raisins. Blend until well combined. Alternatively, you can use a large bowl with an immersion (stick) blender.
Add the oat bran and the remaining raisins to the blended mixture. Mix well and let the batter rest for 15 minutes.
In a separate bowl, whisk together the gluten-free flour blend, baking powder, baking soda, and salt.
Add the dry mixture to the wet mixture and fold in by hand until completely mixed.
Evenly divide the batter between 12 paper-lined muffin cups. Let the filled muffin tin rest while the oven preheats, for 20-30 minutes.
Preheat the oven to 400°F (200°C).
Bake the muffins in the preheated oven until they are golden brown and a toothpick inserted into the center comes out clean, about 15 to 18 minutes.
Allow the muffins to cool in the tin for a few minutes, then transfer them to a wire rack to cool completely.
Enjoy your gluten-free bran muffins as a healthy breakfast or snack. Store any leftovers in an airtight container at room temperature for up to 3 days, or freeze for longer storage.