Preheat oven to 350 degrees. Place a rack in center of oven.

Spread pecans on a large baking sheet and toast in the oven for 6-7 minutes or until fragrant. Remove from oven and set aside.

Generously butter another large baking sheet and set aside on a heatproof surface.

In a small bowl, combine baking soda, cinnamon, sea salt and pumpkin pie spice. Set aside.

Combine sugar, corn syrup and 1/2 cup water in a large saucepan (5 to 6 quart) over medium heat. Stir often with a heatproof spatula until the sugar is totally dissolved.

Bring the mixture to a rolling boil over medium high heat and insert a candy thermometer into the pot. Stir occasionally, until the thermometer reads 230 degrees F.

Add the pecans and the butter and continue to cook, stirring constantly, until the thermometer reads 300 degrees F.

Remove pot from the heat and remove candy thermometer. Quickly stir in the baking soda, cinnamon, salt and pumpkin pie spice from the small bowl along with the vanilla. Mixture will foam, so be careful.Quickly and vigorously stir the mixture until well combined.

Pour the mixture onto the prepared buttered baking sheet. Quickly spread it to a nice even later with the back of the spatula sprayed with non-stick cooking spray. The mixture does not need to fill up the entire tray.

Let cool, about 2 hours. Break into pieces. Can be stored in an airtight container for up to 4 weeks.