Step 1

Preheat oven to 400 degrees and butter small muffin tins. In the bowl of an electric mixer fitted with the paddle attachment, cream 1 cup sugar and butter until smooth. Add the eggs and beat until fluffy.

Step 2

In a glass measuring cup, combine buttermilk and baking soda and set aside. In a small bowl, whisk together flour and salt; add to the butter mixture alternately with the buttermilk, beating until well mixed.

Step 3

In a food processor, grind the raisins and orange zest. Add to the batter and combine. Spoon the batter into the prepared muffin tins and bake until golden brown and firm to the touch, about 12 minutes.

Step 4

Remove the tins to a cooling rack. Brush the tops of the muffins with orange juice and sprinkle with remaining 1/2 cup sugar while still warm; let stand 5 minutes. Remove muffins from pans.