Turn on your pressure cooker and select the Sauté function. Pour the 1 tablespoon of olive oil into the inner pot. Once the pot is hot, add the ground beef and finely diced yellow onion. Cook for 5 to 6 minutes, breaking the meat apart into fine crumbles with a wooden spoon until it is fully browned and no pink remains.

Stir in the minced garlic, dried Italian seasoning, and garlic powder. Season with a pinch of salt and black pepper, and sauté for exactly 60 seconds until fragrant. Turn off the Sauté function.

Use a wooden spoon to firmly scrape the bottom of the inner steel pot, ensuring there are no stuck or caramelized meat bits anchored to the base; a clean bottom is essential to prevent a burn warning.

Take the 8 ounces of dry spaghetti noodles and snap them completely in half. Scatter the broken pasta strands directly over the cooked beef in a criss-cross or layered basket-weave pattern. Avoid dropping the noodles in a single, tight clump, as they will stick together during cooking.

Pour the 3 cups of water or low-sodium beef broth evenly over the pasta layers. Use the back of a spoon to gently press the noodles down just until they are barely submerged in the liquid. Do not stir.

Pour the entire 24-ounce jar of spaghetti sauce directly over the top of the water and noodles. Spread it into a flat, level sheet to cover the pasta completely. Do not stir the pot; keeping the thick tomato sauce floating at the top prevents it from scorching on the hot bottom element.

Secure the pressure cooker lid and turn the venting knob to the Sealing position. Select Manual / Pressure Cook on High for 8 minutes.

It will take roughly 8 to 10 minutes for the machine to build pressure before the countdown timer begins.

The exact moment the cooking timer beeps, carefully perform a Quick Release by moving the venting knob to the Venting position to rapidly discharge the steam. Open the lid once the float valve drops completely.

The spaghetti will look a bit liquid and soupy at first glance—this is completely normal. Use a pair of tongs or a large spoon to stir the pot thoroughly, breaking up any noodles that may have tucked together and blending the top sauce into the bottom pasta water baseline. Let the pot sit uncovered for 5 minutes; the starches will rapidly absorb the residual liquid, tightening the sauce into a thick, glossy coat. Serve hot with a dusting of Parmesan cheese.