Step 1: Preheat the oven
Preheat your oven to 350°F (175°C). Line two baking sheets with parchment paper or a silicone baking mat to prevent sticking. Set them aside.

Step 2: Mix dry ingredients
In a medium-sized bowl, whisk together the flour, baking soda, baking powder, and salt. This will ensure that all dry ingredients are evenly distributed.

Step 3: Cream butter and sugar
In a large mixing bowl, using an electric mixer, beat the softened butter and 1 1/2 cups of granulated sugar together until light and fluffy. This should take about 2-3 minutes. The mixture should be pale in color and fluffy in texture.

Step 4: Add wet ingredients
Beat in the egg, vanilla extract, and milk. Continue mixing until all ingredients are well combined, ensuring a smooth batter.

Step 5: Combine wet and dry mixtures
Gradually add the dry ingredients to the wet mixture. Mix on low speed just until everything is combined. Do not over-mix, as it may result in tougher cookies.

Step 6: Shape the dough
Scoop out 1-2 tablespoons of dough and roll it into a ball using your hands. Roll each ball of dough in the additional granulated sugar until fully coated. This will give the cookies a sweet and crunchy exterior.

Step 7: Bake
Place the dough balls onto the prepared baking sheets, spacing them about 2 inches apart. Gently press each ball down with your fingers or the bottom of a glass to flatten them slightly. Bake in the preheated oven for 8-10 minutes, or until the edges are set and lightly golden. The centers should still look slightly undercooked.

Step 8: Cool
Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely. This helps them set and keeps them soft and chewy in the center.