Preheat the oven to 350°F (175°C). Stir together graham cracker crumbs, melted butter, and sugar until blended. Press the mixture firmly into a 9-inch springform pan. Bake for 8–10 minutes, then cool completely.
Reduce oven temperature to 325°F (163°C). Beat cream cheese and sugar until smooth. Add eggs one at a time, mixing gently after each addition. Blend in vanilla and mashed bananas. Pour filling into the cooled crust. Bake 50–60 minutes, until center is just set. Cool fully, then refrigerate at least 4 hours or overnight.
Whisk banana pudding mix with cold milk until thickened. Spread evenly over the chilled cheesecake.
Spread whipped cream over the pudding layer, then top with sliced bananas and crushed graham crackers.
Refrigerate until ready to serve. Slice cold for the cleanest cuts and best texture.