Preheat the oven to 180°C. Lightly brush a 10/12-hole muffin tray with oil.
Cream the brown sugar and eggs in a large mixing bowl, then add the oil and beat until smooth.
Combine the flour, salt, baking soda, baking powder, and cinnamon. Sift into the wet ingredients. Stir, until just blended. Stir in the vanilla essence, grated carrot and raisins. Pour into the prepared muffin holes. Bake for 25 minutes or until a skewer inserted in the center comes out clean. Cool on a wire rack.
Enjoy as is or if choosing to add icing: Mix the icing sugar and water in a small bowl, then top each muffin with a drizzle of icing.