Preheat your pressure cooker to the bake function.
In a saucepan, combine the Guinness and butter. Heat until the butter is melted and the mixture is hot.
Whisk in the cocoa powder until smooth. Remove from heat and cool slightly.
In a large bowl, whisk together flour, sugar, baking soda, and salt.
In another bowl, beat the eggs, sour cream, and vanilla until smooth. Stir in the slightly cooled cocoa mixture.
Gently fold the dry ingredients into the wet mixture, alternating with the chocolate chips.
Pour the batter into a greased bundt pan that fits into your pressure cooker.
Bake in the preheated pressure cooker for 45 minutes or until a toothpick comes out clean. Let cool before serving.
Notes
Make sure to lightly grease the bundt pan to prevent sticking. Serve with a scoop of vanilla ice cream or a drizzle of chocolate sauce for an extra treat.