In a blender, add the whole lemon chunks, sugar, eggs, vegetable oil, sour cream, vanilla extract, flour, baking soda, baking powder, and salt. Blend for about 30 seconds until everything in combined and resembles a thick cake batter.
1 whole lemon, 1 cup granulated sugar, 3 large eggs, ⅓ cup vegetable oil, ⅓ cup sour cream, 1 teaspoon vanilla extract, 2 cups all-purpose flour, 1 ½ teaspoons baking powder, ½ teaspoon baking soda, ¼ teaspoon salt