Line an 8x8" pan with parchment paper, making sure it hangs over the sides. You can also line with aluminum foil and spray with nonstick spray.
In a large skillet or frying pan over medium heat, melt 1 tablespoon butter. Add chopped pecans and cook (add a pinch of salt, if desired), stirring occasionally, for about 5 minutes or until lightly toasted and fragrant. Transfer to a bowl and set aside.
1/2 cup + 1 tablespoon unsalted butter, 1 cup whole pecans, Pinch salt
In a medium saucepan over low heat, combine remaining 1/2 cup butter, brown sugar, granulated sugar and heavy cream.
1/2 cup + 1 tablespoon unsalted butter, 3/4 cup light brown sugar, 1/4 cup granulated sugar, 1/2 cup heavy cream
Once the butter has melted, give it a quick stir and then bring to a boil. Let boil for 5 minutes - no stirring! If using a thermometer, you want it at 235°F.
Remove from heat and let cool for at least 5 minutes, preferably 10.
Add vanilla and salt, stir to combine.
1 teaspoon pure vanilla extract, 1/2 teaspoon salt
Slowly add in powdered sugar, stirring to combine. It will start to get thick - you may need to put a little muscle in it near the end! Set aside 2-4 tablespoons of pecans, add the rest to the pot, and stir again to combine.
2 cups confectioners’ sugar (powdered sugar)
Press batter into prepared pan, top with your reserved pecans and press them into the top, and let set in the fridge for at least 2 hours. Slice in 24 pieces (or more id you'd like smaller pieces). Enjoy!
Notes
Storage: Slice and place it in an airtight container in between layers of wax paper or parchment paper. Store at room temperature for up to 2 weeks, in the fridge for up to a month, or in the freezer for up to a year.