Preheat the oven to 350 F and grease a 9 x 5 loaf pan with nonstick cooking spray.In a stand mixer with the paddle attachment cream butter until light and fluffy, 2-3 minutes. (This is an important step make sure to cream the butter for a full 2-3 minutes or the cake will fall)Add in sugar and mix for an additional minute.
Add in eggs one at a time and scrape the sides of the bowl with a rubber spatula.
Next add in sour cream and vanilla and mix until combined.
In a medium bowl combine flour, baking powder, baking soda and salt.On low speed add the dry ingredients to the stand mixer and mix just until combined. Do not over mix.
Gently fold in the chocolate chips.
Pour batter into the prepared pan and bake for 1 hour. If the top is getting too brown cover with foil.
Allow the cake to cool for 15 minutes in the pan before turning it out onto a wire rack to cool completely.