Preheat oven to 200 C / Gas 6 and grease a muffin tin or line with paper cases.
In a bowl combine flour, baking powder, salt, 1/4 teaspoon cinnamon, nutmeg, cloves and vanilla sugar. Mix well.
In a separate bowl whisk together eggs, milk, brown sugar and oil, until sugar is dissolved. Add flour mixture and stir until just combined. The mixture can be a little lumpy. Fold in blueberries and spoon the muffin mixture into the prepared muffin tins.
In a small bowl mix caster sugar and 1 teaspoon cinnamon. Sprinkle on top of the muffins.
Bake for 20 minutes in the preheated oven or until a skewer inserted in to the centre comes out clean. Remove from the oven and allow to cool in the tin for a few minutes, remove form the tin and set on a cooling rack until cooled completely.
Vanilla sugar is generally available in supermarkets nowadays, however, in a pinch substitute 1 teaspoon of vanilla extract to every 2 teaspoons vanilla sugar.