Make the pudding: In a large bowl, whisk the instant pudding mixes with cold milk for 2 minutes until thick. Let it sit for 5 more minutes to fully set. Stir in vanilla extract if using.
Prep the bananas: Slice bananas into rounds about 1/4 inch thick.
If you’re worried about browning, lightly toss them with a teaspoon or two of lemon juice. Pat gently with a paper towel to remove excess moisture.
Sweeten the topping (optional): In a small bowl, fold powdered sugar into Cool Whip if you like it a touch sweeter. Don’t overmix.
Layer 1 – cookies: Add a single layer of vanilla wafers to the bottom of a trifle dish (or a large glass bowl).
You can break a few to fill gaps.
Layer 2 – bananas: Arrange a layer of banana slices over the cookies, keeping a few pretty slices for garnish later.
Layer 3 – pudding: Spoon a generous layer of pudding over the bananas. Use a spatula to spread it evenly all the way to the edges.
Layer 4 – Cool Whip: Add a layer of Cool Whip, smoothing the top without pressing too hard.
Repeat the layers: Continue layering cookies, bananas, pudding, and Cool Whip until you reach the top, finishing with a Cool Whip layer.
Decorate: Top with crushed wafers and a few banana slices. You can also stand whole wafers upright around the edge for a neat look.
Chill: Cover and refrigerate for at least 2 hours, or up to 24 hours.
This allows the cookies to soften and the flavors to meld.
Serve: Scoop with a large spoon, making sure each serving gets a bit of every layer.