In a small bowl, cream butter and sugars. Beat in egg and vanilla; mix well. Combine the flour, baking soda and salt; gradually add to creamed mixture and mix well. Stir in macadamia nuts. Spread into a greased 8-in. square baking dish. Bake at 350° for 15-20 minutes or until golden brown.
For topping, in another small bowl, combine the sugar and butter. Stir in coconut and macadamia nuts. Drop mixture evenly over top of warm bars. Return to the oven and broil 4 in. from the heat for 1-2 minutes or until mixture is bubbly. Immediately sprinkle with chocolate chips. Allow chips to soften for a few minutes, then spread over bars. Cool on a wire rack.