Place Instant Pot rack in bottom of inner liner and add 2 cups water.
Line a 7-inch round cake pan with parchment paper and spray with cooking spray.
Add eggs and sugar to medium-sized bowl. Beat until smooth (about 3 minutes).
Add oil, cocoa powder, vanilla and salt to egg mixture. Beat on low until well combined (about 1 minute).
Add flour to mixing bowl about 1/8 cup at a time, mixing in between, until well combined.
Add nuts and fold into batter with a spatula.
Pour brownie batter into to the prepared baking dish.
Lower baking dish into Instant Pot using a foil sling. Secure lid and set valve to sealing.
Cook on high pressure for 24 minutes. Quick release pressure. Once the pressure is fully released, carefully remove lid.
Using foil sling, lift the baking dish out of the Instant Pot. Set pan aside and allow brownies to cool for 10 minutes.
Cut brownies into squares or triangles to serve.