Preheat Oven: Preheat your oven to 350°F (175°C). Line baking sheets with parchment paper.
Cream Butter and Condensed Milk: In a large bowl, beat the softened butter with the sweetened condensed milk until well combined and creamy. Stir in the vanilla extract.
Combine Dry Ingredients: In another bowl, whisk together the flour, baking soda, and salt.
Mix Together: Gradually add the dry ingredients to the wet mixture, mixing until just combined. Be careful not to overmix.
Add Chocolate Chips: Fold in the chocolate chips (and nuts, if using) until evenly distributed.
Scoop Cookies: Drop tablespoon-sized scoops of dough onto the prepared baking sheets, leaving space between each cookie as they will spread.
Bake: Bake for 10-12 minutes, or until the edges are lightly golden. The centers may look slightly underbaked; they will continue to cook as they cool.
Cool: Allow the cookies to cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.