Preheat the oven to 350℉, and butter a 10-cup bundt pan. Set aside.
Whisk all dry ingredients and set aside.
3 cup All-purpose flour, 1 teaspoon Baking powder, ½ teaspoon Baking soda, ½ teaspoon Salt
Add the lemon zest to the sugar and massage them with your fingertips to release the oil and aroma from the lemon zest.
1½ cups Sugar, 2 tablespoon Lemon zest
Use the whisk attachment or hand mixer to beat the softened butter and sugar until light and fluffy.
1 cup Butter
Add the oil and mix well.
¼ cup Oil
Add the eggs, one at a time and mix well after each. Add the vanilla extract.
4 Eggs, 2 tablespoon Vanilla extract
Mix the buttermilk, sour cream, and lemon juice in a separate bowl.
⅓ cup Lemon juice, ½ cup Buttermilk, ¼ cup Sour cream
Using a rubber spatula, add the dry ingredients alternating with the wet ingredients in three stages. Start and finish with dry ingredients.
Pour the batter into the greased pan and bake for 35-45 minutes or until an insert comes out clean. Let it cool in the pan for 10 minutes, then transfer it to the cooling rack to cool completely.