Heat your oven to 350°F and generously grease a 9x13 inch baking pan (or similar size) with butter or cooking spray, making sure to coat the bottom and all sides. This prevents sticking and ensures even browning on the cake edges.

In a large mixing bowl, combine the yellow cake mix, melted butter, sugar, sour cream, eggs, apricot nectar, vanilla, lemon zest, and salt. Mix on low speed for 1 minute to combine all ingredients, then increase to medium speed and beat for 2 more minutes until the batter is smooth and uniform. I find that sour cream adds incredible moisture to boxed cakes, so don't skip it—it makes a noticeable difference in texture.

Pour the batter into the prepared pan and spread it evenly with a spatula. Bake at 350°F for 40 minutes, or until a toothpick inserted into the center comes out clean or with just a few moist crumbs. The cake will be golden and spring back when lightly touched.

Remove the cake from the oven and let it cool in the pan for 15 minutes. This allows the cake to set slightly and makes it easier to handle. After 15 minutes, turn the cake out onto a wire cooling rack and allow it to cool completely before glazing—about 1 to 2 hours. I always let cakes cool completely before adding glaze so it doesn't melt off or become too thin.

While the cake cools, whisk together the sifted powdered sugar, lemon juice, and apricot nectar in a small bowl until you reach a smooth, pourable consistency. The mixture should be thick but still drizzle-able—if it's too thick, add a touch more apricot nectar; if too thin, add more powdered sugar.

Once the cake has cooled completely, pour or spread the glaze evenly over the top, allowing it to drip down the sides naturally. Let the glaze set for 10-15 minutes before serving. The lemon and apricot flavors in the glaze beautifully complement the tender, moist cake underneath.