Raisin Buttermilk Coffee Cake

In a bowl, combine the first five ingredients until mixture resembles coarse crumbs; set aside. In a mixing bowl, cream butter and sugar. Add eggs, one at a time, beating well after each addition. Combine the dry ingredients; add to creamed mixture alternately with buttermilk. Stir in raisins. Spread half of the batter into a greased 13-in. x 9-in. x 2-in. baking pan. Sprinkle with half of the crumb mixture. Carefully spread with remaining batter and sprinkle with remaining crumb mixture. Bake at 350 degrees F for 35-40 minutes or until a toothpick inserted near the center comes out clean.