Directions
Preheat your oven to 350°F (175°C). Lightly grease a 9×13-inch metal baking pan with nonstick spray or butter, making sure to coat the corners so the cake releases easily.
In a large mixing bowl, combine the dry yellow cake mix and the instant lemon pudding mix. Whisk them together so the pudding is evenly distributed through the cake mix; this helps the cake bake up uniformly tender.
In a separate medium bowl or large measuring cup, whisk together the cold whole milk, neutral oil, eggs, granulated sugar, and vanilla extract until the mixture is smooth and the sugar is mostly dissolved. The milk and extra sugar are key to Aunt Barbara’s moist, almost custardy texture.
Pour the wet mixture into the bowl with the cake and pudding mixes. Add the finely grated lemon zest. Using a hand mixer on medium speed or a sturdy whisk, beat until the batter is thick, smooth, and glossy, about 2
