Make crust: In a medium-bowl, stir together Nilla-wafers, butter & salt. Press into the bottom of a small square baking dish. Put aside.
Make cheese-cake filling: In a large bowl, beat cream-cheese & sugar till fluffy. Beat in heavy-cream & vanilla and till stiff peaks form. Put aside.
In a medium-bowl, whisk together pudding mix & milk. Let pudding stand for 5minutes till thickened. Fold pudding into cheese-cake mix.
Pour the filling into graham cracker-crust. Insert a layer of chopped banana & Nilla-Wafers, then pour remaining portion filling on top. Add a second layer of chopped banana & Nilla-wafers. Refrigerate until set & cool, at least two hours and up to immediately insured.
Top lasagna with cool whip, and sprinkle with nilla-wafers along with remaining banana-slices. Slice and serve.