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 butter and sugar in a large bowl until light and fluffy, about 3 minutes.
04 - Beat in eggs one at a time, mixing well after each addition. Stir in vanilla extract.
05 - Gradually add dry ingredients to wet mixture, alternating with buttermilk. Begin and end with dry ingredients. Mix until just combined.
06 - Toss chocolate chips with 2 tablespoons flour, then gently fold into batter.
07 - Pour batter into prepared pan. Smooth top and sprinkle with coarse sugar or extra chips if desired.
08 - Bake for 35-40 minutes until toothpick inserted in center comes out clean or with moist crumbs.
09 - Cool in pan for 10 minutes, then turn onto wire rack to cool completely. Slice and serve.