In bowl of 6-quart Instant Pot, stir apples, water, lemon juice, brown sugar, cinnamon, ginger, nutmeg and salt until well combined. Secure lid and set Pressure Release to Sealing. Select Pressure Cook or Manual Setting and set cooking time for 15 minutes at high pressure (pot will take about 10 minutes to come to pressure before cooking time begins).

When cooking time ends, let pressure release naturally for 5 minutes, then move Pressure Release to Venting to release remaining steam.

Using immersion blender, carefully blend apples in Instant Pot until very smooth (you will have applesauce at this point!).

Leave applesauce in Instant Pot and select Sauté setting. Cover pot with clean kitchen towel or splatter guard and cook 10 minutes, stirring and scraping bottom once halfway through.

The goal of sautéing is to get the applesauce to reduce down to a thick and smooth apple butter (like a thick jam consistency). Mixture will reduce by half (from about 3 cups to about 1-1/2 cups). Depending on how juicy the apples were to begin with, you may need to sauté for an additional 5 minutes. Watch the mixture extremely closely during this time to prevent burning.

When mixture is very thick and smooth, transfer to airtight container and let cool at room temperature, uncovered, 30 minutes. Transfer to refrigerator and chill at least 4 hours or up to 2 weeks.