Grease bottom and 1/2-inch up sides of a 9x9x2-inch baking pan. Set aside. In a small bowl, pour boiling water over the 1 cup rolled oats. Set aside. Prepare Streusel-Nut Topping; set aside. In a medium bowl, combine the 1-1/2 cups flour, baking powder, baking soda, salt, and cardamom.
In a large mixing bowl, beat butter with an electric mixer on medium speed for 30 seconds. Add the 1 cup brown sugar; beat on medium speed till well combined. Add eggs one at a time beating well after each addition. Alternately add flour mixture and oatmeal mixture to beaten egg mixture; beat on low speed just till combined. Stir in apricots or cherries.
Spoon batter into prepared pan. Sprinkle with Streusel-Nut Topping. Bake in a 350 degree F oven for 55 to 60 minutes or till wooden pick inserted near center comes out clean. Cool on wire rack. Serve warm. Makes 9 servings.
In a small bowl, combine rolled oats, brown sugar, and all-purpose flour. Using a pastry blender, cut in butter till mixture resembles coarse crumbs. Stir in coarsely chopped walnuts.