Add 1 cup unsalted softened butter into a large mixing bowl along with 1/3 cup granulated sugar, and 1 cup golden brown sugar. Use an electric hand mixer to mix the butter and sugar together until it’s creamed together. This should take about 2-3 minutes
Next, add 1 large egg, 1 egg yolk, and 1 teaspoon of vanilla extract. Mix again at high speed for about 1 minute.
Now place a fine-mesh sieve over the mixing bowl and add in 2 1/2 cups all-purpose flour (spooned and leveled off), 1 teaspoon baking soda, and 1 teaspoon salt. Sift the dry ingredients in, then mix again with the hand mixer. You will need to mix at low speed so the flour doesn’t go flying everywhere.
Mix everything together using a spatula. Then scoop out the cookie dough using a medium-sized cookie scoop. Place the cookie dough balls onto a baking sheet lined with parchment paper and bake at 350 degrees Fahrenheit for about 9 minutes. TIP: to make the cookies look prettier you can add extra chunks of Hershey's chocolate, crushed graham crackers, and mini marshmallows on top before baking.