Preheat the oven to 250ºF and adjust the rack to the middle position. Whisk together the egg white, brown sugar, vanilla, sea salt and pumpkin spice blend in a large bowl. Add the pecans and stir until the nuts are throughly coated with the sugar mixture. Spread evenly on a baking sheet lined with parchment paper. Bake, stirring every 15 minutes until the coating has set and started to harden, about 45 minutes. Cool completely. Store in a mason jar or large glass tupperware. You can eat them alone as a snack, serve over ice cream, yogurt or toss with a salad!