Preheat & Prepare Pan: Preheat your oven to 325°F (163°C). Generously grease a 10-inch tube or Bundt pan with butter and dust with flour, tapping out any excess.

Cream Butter & Cream Cheese: In a large mixing bowl, beat the softened butter and cream cheese together on medium speed until light and fluffy, about 3-4 minutes.

Add Sugar: Gradually add the granulated sugar, beating for an additional 5 minutes until the mixture is pale and well combined.

Incorporate Eggs: Add the eggs one at a time, beating well after each addition to ensure a smooth batter.

Flavorings: Mix in the vanilla extract, lemon zest (if using), and sour cream until just combined.

Combine Dry Ingredients: In a separate bowl, whisk together the all-purpose flour and salt. Gradually add this to the wet mixture, mixing on low speed just until incorporated. Avoid overmixing.

Bake: Pour the batter into the prepared pan, smoothing the top. Bake for 65-75 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs.

Cool: Allow the cake to cool in the pan for 15 minutes, then carefully turn it out onto a wire rack to cool completely.