Preheat oven to 350°. Line 13 x 9 pan with a single sheet of foil or parchment paper.  Have the edges of the foil/paper hang over the ends of the pan for lifting the bars out after baking. In mixing bowl, use mixer to cream butter and 1/2 cup brown sugar until smooth.  Mix in 1 1/2 cups flour until crumbly.  Press into bottom of 13 x 9 pan.  Bake 10 minutes.  Crust should be set, but not brown.  Sprinkle chocolate chips over partially baked crust.

While crust is baking, beat eggs with a mixer in another mixing bowl until foamy.  Gradually add 1 1/2 cups brown sugar, beating until thick.  Blend in 1/4 cup flour, baking powder, salt and vanilla.  Fold in coconut and nuts with a rubber spatula.  Set aside.

Spread filling over the chocolate covered cookie crust.  Bake 20 to 25 minutes or until golden brown.  Cool.  Lift foil to remove bars from pan and place on a cutting board.   Cut into 2" square bars.