1In a mixing bowl, cream butter and brown sugar. Combine the flour, cinnamon and baking soda; gradually add to creamed mixture. Stir in the oats, coconut and nuts. Remove 1 cup for topping. Press remaining oat mixture into an ungreased 13-in x 9 in x 2 in baking dish. Bake at 350
2Bake at 350 degrees for 12-13 minutes or until light brown. Cool on a wire rack.
3In a bowl, fold whipped topping into yogurt. Spread over crust. Sprinkle with reserved oat mixture. Cover and refrigerate for 4 hours or overnight.