Directions

1. In a mixing bowl, add butter and sugar and mix until fluffy.
2. Add egg to the sugar mixture. Stir in peanut butter and milk.
3. Using a sieve, sift baking soda and flour and gradually add to peanut butter mixture. Add vanilla extract and mix well.
4. Lightly grease a baking dish (that will fit into cooker). Pour batter into dish. Place steamer rack in cooker and place dish on rack.
5. Close and lock lid and set pressure cooker to "bake", adjust time to 30 minutes, and press "start/stop".
6. Carefully open lid, remove cake. Use a toothpick to see cake is done. If not, cook an additional 5 minutes and follow steps until cake is done. If done, remove the cake. Allow cake to cool. Serve with ice cream.