Combine half & half, eggs, pumpkin, sugar, vanilla extract, and spice. Whisk.
Add bread pieces to custard. Push under so it soaks the custard. Let it sit for 10 minutes.
Layer baking dish with one layer of bread, then half of the pecans and raisins. Repeat.
Loosely cover with foil. Pressure cook at high pressure for 30 minutes.
Enjoy with whipped cream or ice cream and a drizzle of caramel.