In a small saucepan, heat the butter over low heat and cook for 7-10 minutes, stirring frequently until the butter turns golden brown. Remove from heat and transfer to a small bowl to allow to cool until the butter solidifies..
In a large bowl, beat the butter, dark brown sugar and sugar until light and fluffy. Add the eggs, one at a time and beat some more. Scrape down the sides of the bowl. Add the vanilla and mix to combine.
Add the dry ingredients and mix just until combined.
Use a spatula, or spoon, to stir in the toffee chips and pecans.
Chill the dough for at least an hour before baking. Chilling overnight is even better.
When ready to bake cookies, preheat the oven to 350 degrees.
Use a 1 ½” tablespoon cookie scoop to create evenly sized cookie balls. Place the cookie dough onto the baking trays, leaving about 2-3” in between cookies.
Bake for 8-10 minutes, just until the edges of the cookies start to turn golden. Remove and let cool on the baking sheet for 2 minutes to allow the cookies to set.
Optional: Sprinkle the tops with a small amount of sea salt flakes.
Place the cookies on a cooling rack to cool completely.
Notes
Store any leftovers in an airtight container for up to 4 days.