01 - Preheat oven to 350°F. Grease and flour a 9-inch round or square cake pan.
02 - Whisk together flour, baking powder, baking soda, and salt in a medium bowl. Set aside.
03 - Beat softened butter and granulated sugar in a large bowl until light and fluffy, approximately 3 minutes.
04 - Add eggs one at a time, mixing thoroughly after each addition. Blend in vanilla extract.
05 - Gradually incorporate dry ingredients into the wet mixture, alternating with buttermilk. Begin and end with dry ingredients. Mix until just combined, being careful not to overmix.
06 - Toss chocolate chips with 2 tablespoons flour, then gently fold into the batter.
07 - Transfer batter to prepared pan, smoothing the top. Sprinkle with coarse sugar or extra chocolate chips if desired.
08 - Bake for 35-40 minutes until a toothpick inserted in the center emerges clean or with a few moist crumbs.
09 - Let cake cool in pan for 10 minutes, then transfer to wire rack to cool completely. Slice and serve.