||Preheat oven to 325 degrees. Generously grease/spray/flour/etc. a 12 cup Bundt pan and set aside.
In a (very) large mixing bowl, combine flour, sugar, baking powder, salt, butter, milk, eggs, and vanilla. Mix with a hand mixer or stand mixer at medium speed for 3-4 minutes. Spoon half of the batter into pan.
Stir remaining ingredients into remaining batter. Spoon over batter in pan.
Bake for about an hour, or until the cake passes the toothpick test. Cool in pan for 30 minutes, then invert onto serving plate.