Spray a 10-15 cup bundt pan with cooking spray really well. Set aside. Preheat your oven to 325 degrees.
Add the the cake mix, lemon pudding powder (just the dry mix, don't make it) lemon juice, milk, oil, eggs, sour cream & vanilla to a large bowl and mix till combined. Stir in the white chocolate chips if using.
Pour the batter in to the prepared bundt pan. Bake for 50 to 55 min. or until a toothpick comes out clean.
Let it cool then invert it onto a serving plate or cake stand.
In a medium sized bowl, mix the sour cream, zest lemon juice and powdered sugar till smooth. Drizzle over each slice and top with fresh berries if desired.
-If you don't want to make the lemon sour cream sauce, you could top this cake with powdered sugar or a cream cheese frosting as well.
-The white chocolate chips are optional, but I love the added sweetness it gives this bundt cake.
-You could use a yellow cake mix in place of the lemon. It won't be as strong of a lemon flavor though.