Step 1

Preheat the oven to 350 degrees Fahrenheit. Spread the pecan halves on a baking sheet and toast for 3 to 5 minutes until fragrant. Remove them from the oven, and let them cool slightly. Then coarsely chop. Set aside.

Step 2

In a large bowl, combine the melted butter and both sugars. Stir until well combined. Mix in the egg, egg yolk, and vanilla extract until smooth.

Step 3

In a separate bowl, whisk together the flour, cornstarch, baking soda, baking powder, and salt.

Step 4

Gradually stir the dry ingredients into the wet ingredients until just combined. Then, gently stir in the toasted chopped pecans and toffee bits (if using).

Step 5

Line baking sheets with parchment paper. Scoop the dough into rounded 1 1/2 tablespoon balls. Place dough balls 2 inches apart on the prepared baking sheets.

Step 6

Bake at 350 degrees Fahrenheit for 10-12 minutes. The edges should be lightly browned. The centers should still look soft and slightly underbaked.

Step 7

Remove the cookies from the oven and let them cool completely on the baking sheets. They will finish setting as they cool. Sprinkle with flaky sea salt if desired. Enjoy!