Preheat the oven to 350 degrees . Melt 4 ounces unsalted butter with 6 ounces semisweet chocolate; let cool. In a bowl, combine 1 cup flour, 1/4 cup cocoa powder and 1 teaspoon salt. In another bowl, beat 1 1/4 cups sugar, the chocolate mixture and 3 eggs; stir into the dry ingredients. Fold in 1 cup chopped dried cherries. Pour into a greased and floured foil-lined 8-inch square baking pan; bake until a toothpick inserted into the center comes out clean, 45 minutes. Cool on a rack. Cut into 3/4-inch squares.