1. Grease a 6 cup bundt cake pan. 2. Mix flour, baking powder, baking soda, cinnamon and nutmeg. 3. Add mashed bananas, eggs, sugar oil and vanilla. Mix dry and wet ingredients. Add walnuts. 4. Spoon batter into prepared pan. Place a paper towel on top of the pan and cover with foil.  5. Put water and trivet in IP. Seal lid. Set the pot to manual, high pressure for 45 mins. When done, open the quick release valve. Remove the pan from the pot. 6. Remove the paper foil and paper towel. Cool completely before inverting onto a plate. Heat cream cheese icing in microwave for 10 seconds and stir. Drizzle on top of bread before serving.