Add pecans, maple syrup, vanilla, cinnamon, nutmeg, allspice, salt, and cayenne powder to the pot of your pressure cooker. Turn on the Sauté setting and stir well. Cook for 5-10 minutes, stirring constantly.
Cancel the sauté setting. Add the water and stir gently. Place the lid on the pot and turn the steam release knob to the Sealing position.
Press the Pressure Cook (or Manual) button or dial, then the +/- button or dial to select 8 minutes. High Pressure.
While nuts are cooking, preheat oven to 300° F, and line a baking sheet with parchment paper.
When the cooking cycle is finished, turn off the pot and turn the steam release knob to the Venting position to do a Quick Release of the steam. Remove the lid and stir the nuts.
Pour the nuts onto the parchment lined baking sheet and spread them out into a single layer as much as possible.
Bake for 10 minutes. Then remove from oven and stir, place back in oven for about 5 more minutes, but check on them during baking to make sure they don't burn.
Remove from oven and let cool completely before packaging so they will not stick together.