2. Whisk together the flour, sugar, salt and baking powder. Then mix the oil, egg and milk into the flour mixture. Then fold in the blueberries. Pour the mixture onto the muffin tins individually, level with the tops. Then sprinkle some of the other ingredients on top to make it crunchy.
3. For the crunchy tops, mix 100g of sugar, 50g of flour, 50g of butter and 1.5 teaspoons of cinnamon together with a fork and sprinkle onto the muffins.
4. Bake in a preheated oven for 20-25 minutes.