Step 1

Preheat oven to 200 C (390 F) standard / 180 C (350 F) fan-forced. Grease a 12-hole muffin pan well with butter or olive oil spray or use cupcake liners. In a large mixing bowl, add flour, baking powder and sugar and whisk briefly.

Step 2

To a small bowl, add oil, vanilla and eggs and whisk together just to break up the egg yolks. Make a well in the middle of your dry ingredients, add the wet ingredients, along with the buttermilk. Very gently start to fold the mixture using a wooden spoon or spatula.

Step 3

Add blueberries. Fold until the mixture is just combined – be careful not to over mix or your muffins will be tough. Spoon out the mixture into your prepared tin.

Step 4

To make the crumble, stir together the sugar, flour and cinnamon. Add melted butter and stir until it forms a wet paste. Sprinkle over each muffin.

Step 5

Bake muffins for 5 minutes before turning the oven temperature down to 180 C (350 F) standard / 160 C (320 F) fan-forced and bake for a further 13-15 minutes or golden brown on top (and a skewer inserted into the middle comes out clean).