Preheat the oven to 350℉/176℃. Grease a muffin tin very well with oil and set aside. Chop the pecans.
1 cup pecans
In a pot over medium heat, melt the butter. Then add the chopped pecans and stir for 3-4 minutes on medium-high heat until the aroma of toasty pecans fill the air. Remove from the heat and transfer into a heat-safe bowl to cool.
2 tbsp butter, 1 cup pecans
In a bowl, add the dry ingredients. Stir to combine and set aside.
2 1/4 cups all-purpose flour, 1 tsp cornstarch, 1/2 tsp baking soda, 1/4 tsp baking powder, 1/2 tsp salt
In a large bowl, add the butter, brown sugar, and white sugar. Whisk to combine.
1 cup butter, 2/3 cups white sugar, 1/2 cup light brown sugar
Whisk in the egg and vanilla for another minute until well combined.
2 eggs, 1 tbsp vanilla
Add the dry ingredients in and with a spatula, gently fold just until mixed together. Do not over-mix!
Add the toasted pecans and stir in a few times, once again, do not over-mix!
Scoop the cookie dough between the muffin tin evenly. I used a 2 tbsp cookie scooper and made 14 cookie cups total. Place a pecan in the center of each cookie cup (optional).
Bake for 18-22 minutes. The edges will be golden brown, and the middle will look slightly underbaked. It will continue to cool as it bakes!
Allow to cool, then gently run a knife around the edges to pop them out. Enjoy!