Preheat oven to 350F. Line mini muffin pans with 24 paper liners.
Mix together raisin bran, milk and banana. Let this mixture sit for 5 minutes.
Transfer to food processor. Add egg yolk, oil, raisins and sugar. Process for a minute to combine.
Add flour, baking soda, baking powder, salt, cinnamon and ginger to food processor; pulse to combine.
Spoon batter into lined muffin tins (about 1 Tbsp per muffin).
Bake for 12-14 minutes until risen and firm to touch. Remove and cool for 5 minutes then transfer to wire rack to cool completely.
To freeze place baked muffins in a resealable container or freezer bag. Thaw for 30 minutes at room temperature to eat from frozen.
Recipe from Annabel Karmel's Top 100 Finger Foods
To freeze: Place cooled, baked muffins in a resealable container or freezer bag. Remove from freezer and place on countertop for 30 minutes before enjoying.