Combine cream cheese, sour cream, sugar, and vanilla in a medium mixing bowl.
Beat on medium-high speed until smooth and creamy.
In a separate small bowl, combine cookie crumbs and melted butter and mix well.
Divide cookie crumbs evenly among 4 small serving dishes.
Slice 1/4 banana into each dish.
Top with 1/8 cream cheese mixture.
Slice an additional 1/4 banana into each dish.
Sprinkle with additional cookie crumbs as desired and top with banana spears.