Beat butter in the bowl of your electric mixer (fitted with the paddle attachment) until creamy, then add in sugar and beat on medium-high until fluffy, about 3-4 minutes, scraping down the sides if needed. Add in vanilla extract and beat until combined, then add in eggs one at a time, beating after each addition. Continue to scrape down sides if needed. Once combined, add in half of the flour mixer, beating on low until just combined, then add in the milk and sour cream, beating again. Finish but adding the rest of the dry ingredients, just beating until combined or even stirring with a spoon. Remove paddle attachment and fold in chocolate chips with a spatula. Pour in the greased bundt pan and bake for 45-50 minutes, or until cake is set. Do not overbake – cake will be dry! Let cool for about 30 minutes in the pan, then gently invert and let cake cool completely before covering in ganache.