Tourta me yaourti kai stafides (spicy yogurt cake w/ rasins)

1/2 c  Sweet butter or margarine
      1 c  Granulated sugar
      3    Eggs
      2 c  Sifted all-purpose flour
      2 ts baking powder
      1 ts Salt
      1 c  Plain yogurt
      1 ts Baking soda
      1 ts vanilla extract
    3/4 c  Raisins
      1 ts Ground cinnamon
    1/2 ts Grated nutmeg
    1/4 ts Ground cloves
    1/2 c  Chopped walnuts (optional)
 
  Cream the butter and sugar together, then add the eggs, one at a time,
  beating well after each addition.  Meanwhile, sift the flour with the
  baking powder and salt and add gradually to the batter, beating on medium
  speed.  Combine the yogurt with the baking soda and add to the batter, a
  few tablespoons at a time, along with the vanilla.
  
  Mix together the raisins, spices, and if desired, the walnuts.  Pour half
  the batter into a buttered 9-inch-square pan and sprinkle half the raisin
  mixture evenly over it.  Pour in the rest of the batter and top with the
  raisin mixture.  Bake in a moderate oven (350 degrees F) for 40 to 45
  minutes, or until cake springs back to the touch of your finger.  Remove to
  a cake rack and cool in the pan.  Cut into squares or diamond shapes when
  cool.
  
  Note: Cupcakes are more popular than cake squares in the larger Greek
  cities.  This recipe would make a dozen cupcakes.
  
  * Source: The Food of Greece, by Vilma Liacouras Chantiles * Typed for you
  by Karen Mintzias