Orange and Raisin Brownies

Arrange rack in center of oven. Spray a 9-inch square baking pan with non-stick cooking spray and coat with flour. Shake out excess. Heat orange juice in small saucepan over medium heat just to warm. Place raisins in small bowl and pour warm orange juice over them. Let raisins marinate 8 to 10 minutes. Melt chocolate and butter to top of double broiler over simmering water. Stir often until mixture is smooth. Remove from heat; set aside. Beat eggs in bowl on medium speed. Gradually add granulated sugar in thin steam and beat until mixture is pale yellow and thickened. Add vanilla and melted chocolate mixture. Then, on slow speed, mix in flour, baking powder, and orange peel. Stir in raisins with any orange juice in bowl along with walnuts. Pour batter into prepared pan and spread top evenly with spatula. Bake brownies at 350 degrees until top is firm and wooden pick inserted in center comes out slightly coated but not wet, 30 minutes. Cool to room temperature in pan. Cut brownies into 16 squares. Dust lightly with confectioner's sugar.