Line a 9x9 inch square baking pan with parchment paper, leaving a little overhang on the sides. Lightly grease the parchment with a bit of butter or non stick spray.

In a large pot over low heat, melt the unsalted butter. Add the mini marshmallows and stir constantly with a silicone spatula until about 90% melted. Remove from heat.

Stir in the instant banana pudding mix and vanilla extract. Watch as the mixture turns a beautiful, soft yellow.

Quickly add the Rice Krispies cereal and the chopped Nilla wafers. Fold everything together gently but thoroughly.

Once the mixture has cooled slightly but is still warm, fold in the white chocolate chips.

Transfer the mixture to your prepared pan. Use a piece of buttered parchment or a greased spatula to press the mixture down gently. Do not pack it too tightly. Let set at room temperature for 30-60 minutes, then cut into squares.