Chocolate Chip Cake Bar

1 package yellow cake mix
2 eggs
1/4 Cup packed brown sugar
1/4 Cup butter or margarine, melted
1/4 Cup water
2 cups semisweet chocolate chips, divided
1/2 Cup chopped pecans or walnuts (optional)
1/2 Tbsp shortening

-In a mixing bowl, combine the first five ingredients. Beat on medium speed for 2 minutes.
-Stir in 1 3/4 cups of chocolate chips and nuts.
-Spread in a greased 13-in. x 9-in. x 2-in. baking pan.
-Bake at 375° for 20-25 minutes or until lightly browned and a toothpick inserted near the center comes out clean.
-Cool pan completely on a wire rack.
-Cut into bars. (About 24)
-Melt shortening with the remaining 1/4 Cup chocolate chips (about 45 seconds in the microwave); drizzle over the top.

***Allow drizzled chocolate to set completely before stacking on a plate.***