Prepare the butter and wonton wrappers: In a small bowl, add butter, pineapple juice, brown sugar and a pinch of salt. Zap for 30 seconds. Add wonton wrappers into melted butter mixture.
Fill the mugs: Toss walnuts and chocolate chips in a bowl. Divide the bananas into 6 portions. In the bottom of two 12-ounce mugs (1 1/2 cups capacity), add 1 portion of the bananas. To both mugs, add a pinch of the walnut and chocolate chip mixture; then pour over a spoonful of the melted butter mixture and layer on a wonton wrapper. Repeat the layers, with the last third of bananas in each mug, topped by the last third of walnuts and chocolate chips and the remaining melted butter mixture.
Zap the mugs! Place mugs in the microwave for 2 1/2-3 minutes. Remove and allow mug to cool slightly, then eat.
Zapping time: 2-3 minutes