1️⃣ Preheat oven to 325°F. Grease a 9-inch springform pan and line the bottom with parchment.
2️⃣ Mix crushed Nilla Wafers, sugar, and melted butter. Press into pan bottom. Bake 8–10 mins and cool.
3️⃣ Beat cream cheese and sugar until smooth. Add mashed banana and mix well. Add eggs one at a time, then stir in vanilla and sour cream. Pour over crust.
4️⃣ Bake 55–65 mins until just set. Turn off oven and let cool inside for 1 hour. Chill at least 4 hours or overnight.
5️⃣ Beat pudding mix with cold milk and cream until thickened. Spread over chilled cheesecake.
6️⃣ Whip heavy cream with powdered sugar until soft peaks form. Dollop or pipe on top. Add banana slices and crushed wafers before serving.
Notes
You can make this 1–2 days ahead — it gets better as it chills.
Keep banana slices fresh with a little lemon juice if prepping in advance.