Preheat oven to 350°F (175°C). Grease a 9x5-inch loaf pan or line with parchment paper.
Beat butter, sugar, and cream cheese together until light and fluffy.
Add eggs one at a time, mixing well. Stir in lemon juice and lemon zest.
In a separate bowl, whisk flour, baking powder, baking soda, and salt.
Add dry ingredients to the wet mixture, alternating with buttermilk, mixing just until combined.
Pour batter into prepared pan and bake for 50–60 minutes, until a toothpick inserted comes out clean.
Cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.