Preheat oven to 325 degrees F. Combine shortening and salt. Add 1/2 cup of the brown sugar and cream well. Add the 1 cup flour and blend. Spread in a greased 12x8-inch pan. Bake for 20 minutes, or until firm and golden brown. Add remaining 1 cup brown sugar and the vanilla to the eggs, beating until thick and foamy. Then add the 2 tablespoons flour, baking powder, coconut, and nuts and blend. Spread over baked mixture. Return to oven and bake for 25 minutes. Cool and cut into small bars.