Start by preheating your oven to 350°F (175°C). Line a baking sheet with parchment paper or a silicone baking mat. This step helps ensure the cookies bake evenly and don’t stick to the tray.

In a large mixing bowl, combine the softened butter, granulated sugar, and brown sugar. Use a hand mixer or stand mixer to beat the mixture on medium speed until it’s light and fluffy. This will take about 3 minutes. Creaming the butter and sugars properly is key to achieving soft, tender cookies.

Add the eggs one at a time, making sure to mix well after each addition. Then, add the vanilla extract and mix until fully combined. These ingredients will give your dough that rich, flavorful base.

In a separate bowl, whisk together the flour, cocoa powder, baking soda, and salt. Gradually add this dry mixture to the wet ingredients, mixing on low speed. Make sure everything is incorporated, but be careful not to overmix the dough.

Once the dough has come together, add the milk. This helps make the dough softer and easier to handle. Mix just until the dough becomes smooth and slightly sticky.

Use a cookie scooper or a tablespoon to scoop out the dough and place it onto the prepared baking sheet. Space the dough balls about 2 inches apart, as the cookies will spread as they bake.

Place the baking sheet in the oven and bake for 12-15 minutes. Keep an eye on them after the 12-minute mark. They should be set around the edges but still soft in the center. For a slightly firmer cookie, let them bake an extra minute or two.

Allow the cookies to cool on the baking sheet for 2-3 minutes before transferring them to a wire cooling rack. This helps them firm up and makes them easier to handle.