Preheat oven to 325 degrees F. Grease and flour an 8 ½ by 4 ½ inch loaf pan. You may want to line it with a strip of parchment before flouring, but that is optional.
In a large bowl, whisk together the flour, baking soda and salt. Set aside.
In the bowl of a stand mixer, combined softened butter, cream cheese, sugar and lemon zest. Beat with the paddle attachment on medium, increasing a little after the first 3 minutes, and scraping the bowl often.
Add one egg and beat on low until it is incorporated, then increase speed and beat for 30 seconds. Repeat with the remaining two eggs.
Add flour in two parts, stirring until blended. Scrape bow and beat on medium for 30 seconds.
Transfer to the pan and spread evenly. Bake at 325 for 1 hour and 5 minutes or up to 1 hour and 10 minutes or until skewer comes out clean. Let cool in the pan for about 10 minutes then run a knife between the cake and the sides of the pan and tip the cake to loosen. Remove from pan.
Let cool completely. To store, let cool completely, wrap in plastic and put wrapped cake in a freezer bag. Freeze.