Preheat oven to 325^. Spray a 9x13-inch cake pan with non-stick baking spray; set aside.
After you make the Cake Mix Batter - remove and set aside the 2/3 cup of the batter. Spread the remaining cake mix batter into the prepared cake pan and bake for 15 minutes to partially bake the crust.: just until lightly brown.
Now mix the reserved 2/3 cup of the cake batter with the syrup,eggs, sugar, extract and roughly chopped pecans.
Pour this mixture on top of the partially baked cake crust and bake for about 55-60 minutest or until set. Test by inserting knife about 1 inch off center of pie to see if it comes out clean;if it does it's baked long enough. Cool on wire rack.
Drizzle with frosting and garnish with whole pecans.