Preheat the oven to 350°F (175°C). Line two baking sheets with parchment paper.
In a medium bowl, whisk together the all-purpose flour, baking soda, baking powder, and salt. Set aside.
In a large bowl, using an electric mixer, cream the softened unsalted butter and granulated sugar together on medium speed until light and fluffy, about 3 to 4 minutes.
Add the egg and pure vanilla extract to the butter mixture and beat until combined.
Gradually add the dry ingredients to the wet ingredients, mixing on low speed until just combined.
Add the whole milk and mix until the dough comes together and is smooth.
Using a tablespoon or cookie scoop, scoop dough and roll into balls. Place them about 2 inches apart on the prepared baking sheets.
Gently flatten each dough ball with the bottom of a glass or your palm to about 1/2 inch thick.
Bake in the preheated oven for 8 to 10 minutes, or until the edges are lightly golden but the centers are still soft.
Remove from the oven and allow cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.