Preheat oven to 350. Spray a 12-cup bundt pan with non-stick spray or butter and flour pan.
In a medium bowl, whisk together the flour, lemon zest, baking soda, and salt. Set aside.
Beat the butter and sugar together on medium-high speed until light and fluffy, 3-5 minutes. Scrape down the sides of the bowl. Add the eggs one at a time, beating well after each addition.
Turn the mixer on low and alternately add the flour and buttermilk, beginning and ending with the flour. Mix until just incorporated.
Spoon the batter into the prepared pan. Shake the pan gently and knock it on the counter a couple of times to settle.
Bake 50-55 minutes or until toothpick comes out clean.
Cool in the pan on a rack for 30 minutes, then unmold onto the rack to cool completely.