Pineapple Crumb Bars

Preheat oven to 350 °F (175°C). In a large mixing bowl combine flour, oatmeal, brown sugar and baking soda. Cut in butter until the mixture resembles coarse crumbs. Remove 1/2 cup of the crumb mixture, adding the macadamia nuts, and set aside. Press remainder of the dough into bottom of an ungreased 9-inch baking pan. Combine sugar and cornstarch in a saucepan; stir in pineapple chunks, orange juice and orange peel. Cook, stirring until thick and bubbly, then spread over crumb layer. Sprinkle reserved crumb mixture on top and press in lightly. Bake for 30 to 35 minutes or until top is golden. Remove from oven and let cool before cutting into bars.