1. Preheat oven to 350 F or 180 C
2. Grease muffin tray, or use silicone trays or muffin cases
3. In a medium, bowl mix butter and sugar together with a fork
4. In a separate bowl, beat together milk and egg
5. Add milk/egg mixture slowly to your butter/sugar bowl, mixing in between with a fork
6. Add your flour, baking powder, and baking soda
7. Do not beat smooth, leave batter slightly lumpy
8. In a separate bowl, using a fork, slightly smash blackberries, leaving some whole
9. Add to batter and stir in gently, leaving a swirl effect
10. Pour batter into muffin tray or cases
11. Bake for 18 minutes or until golden brown (cooking times may vary in various ovens)

To Serve

1. Cut across the middle, add a thin layer of butter while still warm, and serve with coffee, tea or a glass of cold milk.