Preheat oven to 350 degrees F and grease a 9×13 baking dish.
In a small bowl, combine the flour, butter, brown sugar, and 1 cup finely chopped pecans and work the mixture into a crumble using your hands. Press the mixture into the bottom of the 9×13 and bake for 15 minutes.
In a large bowl, whisk together both pudding mixes and milk until smooth. Add in the cream cheese, powdered sugar, and 1 cup cool whip and whisk until fully combined.
Pour pudding mixture over the cooled crust and top with 2 cups of cool whip. Sprinkle with the remaining pecan pieces.
Served chilled and refrigerate any leftovers in an airtight container.