Heat oven to 325 degrees. Grease 12 regular muffin tins. Cream margarine and sugar together. Add egg, baking powder, spices, vanilla and milk. Add half the flour and mix well. Add remaining flour and blackberries. Divide batter among the muffin tins and place 1-2 blackberries on top of each.
Bake 20-30 minutes. Allow to cool 5-10 minutes before removing from tins.