Preheat the oven to 180C (356F) and place 18 paper muffin liners into your muffin tins. If you're not using paper liners, simply grease the muffin tins generously with butter.
Take the raisins and pour the orange juice over them. Allow them to sit for 10 minutes before you start making the muffins.
Shred your apple and carrots and zest your orange (see notes for easy way to do this).
Take all of the wet ingredients, including the orange juice soaked raisins and add them to a large bowl. Whisk them together until the eggs are beaten and all of the wet ingredients are combined. The mixture will be very liquidy - and that's ok!
Now take all of the dry ingredients (except the raisins because they are in the bowl with the wet ingredients already) and add them to a large mixing bowl. Mix them together until everything is well distributed and there are no lumps.
Make a well in the centre of the dry ingredients and pour the wet ingredients into it. Stir the wet and dry ingredients until the dry ingredients are just moistened. It's ok if there are still some dry flour clumps.
Take your muffin tin and scoop the mixture into the holes (or paper liners if you're using them).
Top each muffin with some of the seed mix.
Bake the Sourdough Morning Glory Muffins in the oven at 180C (356F) for around 30 minutes or until baked through and golden (the time will depend on the size of muffins you're making).
Allow to cool on a wire rack.