Mix butter, vanilla, cinnamon, brown sugar and 2 tablespoons of pecans together. Reserve remaining 1 tablespoon of pecans to add to the top.
Fill cored apples with butter, cinnamon, brown sugar and pecan mixture.
Once filled, top apples with remaining 1 tablespoon of pecans.
Place apples into insert pan.
Using a sling-place insert pan onto sling and lower into the Ninja Foodi.
Not using a sling- place trivet into Ninja Foodi and place insert pan on top of trivet.
Close Ninja Foodi pressure cooking lid and move valve to "seal" position.
Select pressure cooker function and cook on high pressure for 4-6 minutes based on how you like your apples. 4 Minutes will create a soft center with a dense outside. 6 minutes will create a soft center and outside.
When timer beeps, allow pressure to naturally release for 4 minutes and then quick release remaining pressure.
Remove lid and carefully lift apples out of Ninja Foodi.