1) Slice off chunks of unpeeled apple around the core and toss the core. (Using a variety of apples gives the applesauce a more complex flavor.)
2) While doing this, bring 1/2 cup of water to boil in the cooker.
3) Toss in the apples–add some pears, if you like. Add some dried cranberries, raisins, or prunes and a pinch of cinnamon, if you feel like having gussied-up applesauce.
4) Lock the lid in place and bring to high pressure over high heat. As soon as high pressure is reached, turn off the heat and let the pressure come down naturally, about 10 minutes.
5) Give a stir and sweeten to taste with sugar, agave or maple syrup. Squeeze in a little lemon juice to sharpen the flavors if that idea sings to you.