In a large mixing bowl, combine melted unsalted butter with granulated and brown sugars, creaming them together until light and fluffy, about 2-3 minutes.

Mix in 1 large egg and 1 teaspoon of vanilla extract until smooth and creamy. Gradually add 2 cups of all-purpose flour, 1 teaspoon of cinnamon, 1 teaspoon of cornstarch, 1 teaspoon of baking soda, and 1/2 teaspoon of baking powder. Stir gently until just combined.

Gently fold in 1 cup of toasted pecans and any optional toffee bits, ensuring even dispersal.

Cover the bowl with plastic wrap and refrigerate the dough for about 30-45 minutes.

Preheat your oven to 350°F (175°C). Use a cookie scoop to portion the dough and roll into balls, about 1.5 inches in diameter.

Bake the cookies for 11-14 minutes until edges are golden brown and centers are soft.

Let cookies cool on the baking sheet for about 5 minutes before transferring to a wire rack.