4 ounces Hershey’s Unsweetened Baking Chocolate

1/3 cup unsalted butter

1 3/4 cups unsifted flour

1 1/2 cups granulated sugar

1 1/2 teaspoons baking soda

1 teaspoon salt

1 1/2 cups sour cream

2 eggs

1 teaspoon vanilla

Melt baking chocolate and butter on top of a double boiler over hot, not boiling water; cool.  Combine remaining ingredients in a large bowl; blend in melted chocolate.  Beat 3 minutes at medium speed.  Pour into two greased and floured 9-inch round cake pans.  Bake at 350° for 30 to 35 minutes or until the cake tester inserted comes out clean.  Cool 10 minutes; remove from pans.  Cool completely on wire racks; frost.