Preheat oven to 425 degrees F (220 degrees C). Grease 12 muffin cups or line with paper muffin liners.
In a large bowl, combine flour, baking powder and salt. Cut in shortening until mixture resembles coarse cornmeal. Add milk all at once to dry ingredients and stir with a fork until a soft dough is formed. Turn dough out onto lightly floured surface and knead gently 8 to 10 times. Roll out to a 12 inch square.
Gently spread butter over dough. Combine brown sugar, cinnamon and raisins. Sprinkle evenly on top of dough. Roll up dough lightly like a jelly-roll. Seal edge. Cut into twelve 1 inch thick pieces. Place in prepared muffin tins.
Bake in preheated oven for 14 to 18 minutes, until golden. Remove from heat immediately. Serve warm.