Step 1: Prepare the Lemon Pudding

In a large mixing bowl, add both boxes of instant lemon pudding. Pour in the milk and whisk for 2 minutes until thick and smooth.

Step 2: Fold in the Whipped Topping

Gently fold the thawed Cool Whip into the pudding mixture until fully combined. The mixture should be light, fluffy, and evenly blended.

Step 3: Layer the Graham Crackers

Arrange a single layer of graham crackers across the bottom of a 9×13-inch baking dish, breaking crackers as needed to fit snugly.

Step 4: Add the Pudding Layer

Spread half of the lemon pudding mixture evenly over the graham crackers using a spatula.

Step 5: Repeat the Layers

Add another layer of graham crackers, followed by the remaining pudding mixture. Smooth the top evenly.

Step 6: Final Graham Cracker Layer

Top with one final layer of graham crackers, covering the entire surface.

Step 7: Warm and Spread the Frosting

Remove the lid and foil seal from the lemon frosting. Microwave uncovered for 20–30 seconds until pourable. Stir well.

Pour the frosting over the top graham cracker layer and spread evenly to the edges.

Step 8: Chill to Set

Cover the dish and refrigerate for at least 8 hours, preferably overnight, to allow the graham crackers to soften into cake-like layers.