Preheat Oven: Preheat your oven to 350°F (175°C). Line baking sheets with parchment paper or lightly grease them.

Cream Butter and Sugar:

In a large mixing bowl, cream together the softened butter and packed brown sugar until light and fluffy.

Add Eggs and Vanilla:

Beat in the eggs one at a time, ensuring each is well incorporated before adding the next.

Mix in the vanilla extract.

Combine Dry Ingredients:

In a separate bowl, whisk together the all-purpose flour, baking soda, and salt.

Alternate Adding Dry Ingredients and Sour Cream:

Gradually add the dry ingredients to the butter mixture, alternating with the sour cream. Start and end with the dry ingredients. Mix until just combined after each addition.

Scoop Dough:

Using a cookie scoop or tablespoon, drop rounded balls of dough onto the prepared baking sheets, spacing them about 2 inches apart.

Bake Cookies:

Bake in the preheated oven for 10-12 minutes, or until the edges are lightly golden. The centers may still look slightly soft.

Cool Cookies:

Allow the cookies to cool on the baking sheets for 5 minutes before transferring them to a wire rack to cool completely.