160g canned blueberries (use only the blueberries and discard the rest of the contents)
Sift the flour, baking powder and salt together. Grease a 12-cup muffin pan. Preheat oven to 200 ºC. Put sifted ingredients into a mixing bowl. Whisk eggs until blended, then add the melted butter, essence, milk and lemon or orange rind. Stir well to combine.
Put sifted ingredients into a mixing bowl. Make a well in the centre and pour in the egg mixture. Use a large metal spoon to stir until the flour is moistened and not lumpy or until the mixture becomes smooth.
Stir in the blueberries and mix. Spoon the batter into the muffin cups, filling them until they're 3/4 full.
Bake in a preheated oven for 20 to 25 minutes or until the muffins spring back when they are pressed lightly.
Leave the muffins to cool slightly in the pan for five to six minutes before turning out.