In a bowl, with an electric mixer on medium speed, beat butter, 1/2 cup granulated sugar, and the brown sugar until smooth. Beat in eggs, vanilla, and orange peel until well blended.
In another bowl, mix flour, baking powder, baking soda, and cinnamon. Stir or beat into butter mixture until well blended. Stir in apricots and raisins.
Spread batter evenly in a buttered and floured 10- by 15-inch baking pan. Bake in a 350° oven until center springs back when pressed and bar is no longer wet in the center (cut to test), 20 to 25 minutes.
Meanwhile, in a 1- to 1 1/2-quart pan, combine remaining 1/2 cup granulated sugar, the apricot brandy, and 1 tablespoon lemon juice. Bring to a boil over high heat; remove syrup from heat and let stand. In a bowl, stir remaining 4 teaspoons lemon juice and the powdered sugar until smooth.
Spoon apricot syrup evenly over warm bar. Let cool completely, then cut into 36 bars. Drizzle lemon icing over bars in pan.
Note: Nutritional analysis is per bar.