PREHEAT oven to 375° F. Grease 9-inch-round cake pan.
COMBINE flour, sugar, baking powder and baking soda in large bowl. Using pastry blender or 2 knives, cut in butter until mixture resembles coarse crumbs. Stir in raisins and morsels. Combine buttermilk and egg in small bowl. Add to flour mixture; stir until dry ingredients are just moistened. Transfer dough to lightly floured board. Knead dough for about 3 minutes, adding a little flour to prevent sticking. Shape into a flattened 8-inch circle. Place in prepared pan. Score top of dough with sharp knife to form an “X”, about 1/2-inch deep. Combine egg yolk and water in small bowl. Brush mixture on top of bread.
BAKE for 35 to 40 minutes or until wooden pick inserted in center comes out clean and top is golden brown. Cool for 10 minutes; remove to wire rack. Serve warm or at room temperature. Store tightly covered in plastic wrap.