01 - Peel, core, and slice apples into uniform 1/2-inch wedges for even cooking.
02 - Arrange apple slices in the Instant Pot insert. Sprinkle brown sugar, cinnamon, nutmeg if using, and salt evenly over the top.
03 - Drizzle maple syrup or honey if desired, then pour in water or apple juice around the edges.
04 - Distribute butter pieces evenly across the apple mixture.
05 - Seal the Instant Pot lid and ensure vent is set to sealing position. Cook on high pressure for 2 minutes.
06 - Allow natural pressure release for 3 minutes, then carefully quick-release any remaining pressure.
07 - Open lid and stir in vanilla extract. For a thicker sauce, select Sauté mode and simmer 2-3 minutes, stirring gently until desired consistency.
08 - Serve immediately as a warm dessert, or use as topping for oatmeal, pancakes, waffles, or ice cream.