Prep the pan: Grease a 7-inch round cake pan or a 6-cup bundt/loaf pan that fits inside your pressure cooker. Line the bottom with parchment and lightly flour the sides. This makes unmolding much easier.

Set up the cooker: Add 1 1/2 cups water to the pressure cooker. Place a trivet or rack inside. You’ll set the cake pan on top so it’s not sitting directly in the water.

Mix the dry ingredients: In a medium bowl, whisk flour, cocoa, sugar, baking powder, baking soda, salt, cinnamon, and cayenne until evenly combined. Break up any cocoa lumps.

Combine the wet ingredients: In a separate bowl, whisk milk, oil, eggs, and vanilla until smooth. Stir in the hot coffee or water. The heat helps bloom the cocoa for deeper flavor.

Make the batter: Pour the wet mixture into the dry ingredients and whisk just until combined. Don’t overmix. If using chopped chocolate, fold it in now.

Fill the pan: Transfer the batter to the prepared pan. Tap the pan gently on the counter to release air bubbles. Cover tightly with foil to prevent excess moisture from dripping onto the cake.

Pressure cook: Place the pan on the trivet. Seal the lid. Cook on High Pressure for 35 minutes (electric models) or maintain pressure for the same time on stovetop models. The cake will rise and set through steam, not browning like in an oven.

Natural release: Let the pressure release naturally for 10 minutes. Then quick-release any remaining pressure. Carefully lift out the pan using a sling or oven mitts.

Check doneness: Remove the foil. A tester inserted near the center should come out with a few moist crumbs, not wet batter. If underdone, re-cover and cook under pressure for another 3–5 minutes.

Cool and unmold: Cool the cake in the pan for 15–20 minutes. Run a thin knife around the edge, then invert onto a plate and peel off the parchment. Let it finish cooling or serve slightly warm.

Finish and serve: Dust with powdered sugar or cinnamon sugar. For a richer finish, pour a quick ganache (equal parts hot cream and chopped chocolate) over the top. Serve with whipped cream or vanilla ice cream.