In a large bowl, whisk together the pudding mixes and cold milk until the mixture thickens (about 2 minutes).

Gently fold in the whipped topping until smooth.

In a 9×13-inch dish, lay down a single layer of graham crackers at the bottom.

Spread half of the pudding mixture over the crackers.

Top with a layer of sliced bananas.

Repeat with another layer of graham crackers, followed by the remaining pudding and more banana slices.

Finish with a final layer of graham crackers on top.

For the ganache: Heat the heavy cream in a small saucepan until just simmering. Pour it over the chocolate chips, let sit for 2 minutes, then stir until smooth.

Pour the ganache over the top cracker layer, spreading it evenly.

Cover and refrigerate for at least 4 hours (overnight for best results) before serving.