Preheat the oven to 200°C (gas mk 6, 400°F). Place the eggs, oil, sugar and milk in a large mixing bowl and beat together.

Add the flour, salt, baking powder and cinnamon, and stir in thoroughly.

Peel and core the apples, then cut them into small pieces. Gently stir the apples and blackberries into the mixture.

Fill a muffin tray with paper muffin cases, and then fill each case to about two thirds full with the muffin mixture.

Rub together the extra flour, extra sugar and butter, until the mix resembles bread crumbs. Sprinkle over the top of each muffin. Alternatively simply sprinkle sugar over the tops of the muffins.

Bake the muffins for 20-25 minutes.

This recipe makes approximately 18 muffins.