Heat oven to 350 degrees. In medium bowl, combine flour and 1/4 cup sugar; mix well. With pastry blender or fork, cut in 1/2 cup butter until mixture resembles coarse crumbs. Press mixture in bottom of ungreased 8-inch square pan. Bake at 350 degrees for 20-25 minutes or until light golden brown. Cool 10 minutes.
Meanwhile, beat egg slightly in medium bowl. Add all remaining topping ingredients except pistachios and coconut; mix well. Stir in pistachios and coconut.
Remove pan from oven. Spoon and spread coconut mixture evenly over warm base. Return to oven; bake an additional 15-20 minutes or until edges are golden brown. Cool 1 hour 15 minutes or until completely cooled. Cut into bars.