Preheat oven to 350°F (175°C) and position rack in the center. Grease a 9x5-inch loaf pan with butter or cooking spray, and optionally line the bottom with parchment paper for easy removal.
In a medium bowl, whisk together the flour, baking powder, and salt for about 30 seconds until evenly combined. Set aside.
In a large bowl, beat the softened butter and sugar together on medium-high speed for 2–3 minutes until light, fluffy, and pale, scraping down the sides halfway through.
Add the eggs one at a time, beating well for about 30 seconds after each addition, then mix in the vanilla extract until fully incorporated.
Beat in the sour cream on low speed until incorporated, then add the milk and mix until the wet ingredients are smooth and combined.
With the mixer on low (or using a wooden spoon), gradually add the dry ingredients and mix just until no dry streaks remain, about 30–45 seconds — do not overmix.
Using a rubber spatula, gently fold in the chocolate chips (reserving about 2 tablespoons for topping) until evenly distributed throughout the batter.
Pour the batter into the prepared pan, smooth the top with a spatula, tap the pan gently on the counter 2–3 times, then sprinkle the reserved chocolate chips over the top.
Bake for 55–65 minutes until a toothpick inserted in the center comes out with just a few moist crumbs; tent loosely with foil after 40 minutes if the top is browning too quickly.
Cool the bread in the pan on a rack for 10–15 minutes, then turn out and cool completely (about 1 hour) before slicing with a serrated knife for clean slices.