Lightly spray 8x8 baking dish with cooking spray and line with parchment paper. Leave an overhang so you can pull the caramel out easily. Set aside.

Combine first four ingredients in a large heavy bottomed pot. Go bigger than you think you need.

Bring to a boil over medium-high heat, stirring occasionally to dissolve the sugar. It's super important to scrape off all the sugar from the sides of the pot - all of it.

Reduce heat to medium and continue cooking WITHOUT stirring until it reaches 248 °F. This can take anywhere for 20 minutes to an hour, just be patient. (Make sure you check the accuracy of your candy thermometer beforehand.)

Remove from heat and stir in salt and pumpkin pie spice.

Pour mixture into prepared baking dish. Let it rest for 12-24 hours before cutting into pieces.

Wrap caramels in waxed paper to store. Can be stored in the fridge or at room temperature.