Pre-heat oven to 350ºF.
In a mixing bowl, combine flour, melted butter, and walnuts, mixing to make a dough. Spread evenly on a sheet pan and bake for 20 minutes. Allow to cool before crumbling.
With a mixer, or by hand, beat cream cheese with Splenda. Carefully fold 1/2 to 2⁄3 of the container of whipped topping into the sweetened cream cheese until smooth, light and fluffy. Scrape into a piping bag, set aside.
In the same bowl, add milk and instant pudding, whipping until smooth. Beat in the bananas to create a thickened banana pudding. Set aside.
Fill the bottom of each individual trifle cup with about 2 tbsp. of the crumbled dough and a few chocolate chips.
Pipe in a layer of sweetened cream cheese on top of the crumbs/chips.
Spoon a thick layer of the banana pudding over the cream cheese layer.
Dollop the top of each cup with remaining whipped topping, chocolate chips, and nuts.
Cover loosely and refrigerate until set and serve.