Preheat oven to 350F. Spray 12 cup bundt pan with non stick spray.
In medium bowl, whisk flour, lemon zest, baking soda, and salt. Set this aside.
In a mixer with the paddle attachment, beat butter and sugar on medium high speed until light and fluffy. Scrape down sides and add eggs one at a time, beating well after each.
Turn mixer to low and alternately add the flour and buttermilk. Begin and end with flour. Mix just until incorporated.
Spoon batter into prepared pan. Knock on counter a couple times to settle any bubbles.
Bake for about 50-55 minutes.
Cool in the pan for about 30 minutes, then unmold onto a cooling rack.