Moist Lemon Cake (Doctored Cake Mix Recipe)

a slice of three-tier moist lemon cake on a white plate.

Moist Lemon Cake (Doctored Cake Mix Recipe)

Course: Cake, Dessert

Cuisine: American

Prep Time: 45

Cook Time: 23

Cool/Chill Time: 4 25

Total Time: 5 33

Servings: slices

Calories: 748kcal

Author: Becky Hardin

This extra moist lemon cake recipe starts with a simple box mix but tastes completely homemade thanks to the addition of sour cream and buttermilk. Topped with a zesty, whipped lemon buttercream, it’s a foolproof, tangy citrus dessert perfect for any celebration.

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US Customary - Metric

Equipment

Kitchen Scale (optional)
3 8-inch Round Cake Pan(s)
Hand Mixer or Stand Mixer
Piping Tip Set (optional)

Ingredients

For the Cake:

15.25 ounces lemon cake mix (1 box)*
1 cup all-purpose flour
1 cup granulated sugar
1½ cups buttermilk room temperature**
1 cup full-fat sour cream room temperature***
3 large eggs room temperature
2 tablespoons fresh lemon juice (from 1 lemon)
1 tablespoon fresh lemon zest (from 1 lemon)

For the Frosting:

6 cups powdered sugar
1½ cup unsalted butter slightly melted (3 sticks)
¼ cup fresh lemon juice (from 2 lemons)
Gel food coloring yellow (optional)****
Sprinkles optional

Instructions

For the Cake:

Preheat oven to 350°F. Spray three 8-inch round cake pans with nonstick spray and line the inside bottom of each pan with parchment paper. Set aside.
In a large bowl, stir the lemon cake mix, flour, and granulated sugar together. Set aside.
15.25 ounces lemon cake mix, 1 cup all-purpose flour, 1 cup granulated sugar
In a separate medium bowl, use a hand or stand mixer to beat the buttermilk, sour cream, eggs, lemon juice, and lemon zest together on low speed until well mixed, about 2 minutes.
1½ cups buttermilk, 1 cup full-fat sour cream, 3 large eggs, 2 tablespoons fresh lemon juice, 1 tablespoon fresh lemon zest
Pour the wet ingredients into dry ingredients and beat on low speed until well mixed, about 1 minute.
Divide the cake batter evenly between the prepared cake pans (about 508 grams per pan).
Bake for 23-25 minutes, or until a toothpick inserted in the middle of the cakes comes out clean.
Remove the cakes from the oven, and them let cool in their pans for 15 minutes before unmolding and letting cool completely on a wire rack, about 2 hours.
Once cooled, wrap each cake individually in plastic wrap and chill in the refrigerator for 2 hours.

For the Frosting:

In a large bowl, using a hand or stand mixer, beat the powdered sugar, butter, and lemon juice on high speed until light and fluffy, about 5 minutes.
6 cups powdered sugar, 1½ cup unsalted butter, ¼ cup fresh lemon juice

For Assembly:

Remove the cakes from fridge, unwrap, and use a large serrated knife to cut the dome tops off all cake layers so they are level.
Place a thin layer of frosting (about 2 tablespoons) in the middle of a cake board or cake plate then place one cake (cut side facing up) on top of that frosting.
Add a generous layer of frosting on top of that first layer, smooth it out evenly, then place the second layer (cut side facing up) on top of the first layer.
Add a generous layer of frosting on top of that second layer, smooth it out evenly, then place the third layer (bottom side facing up) on top of that frosted second layer.
Crumb-coat the entire cake with a thin layer of frosting. Use a cake scraper to smooth it out.
Place the crumb-coated cake in the freezer for 10 minutes to firm up.
While the cake chills, optionally color the remaining frosting yellow with gel food coloring.
Gel food coloring
Remove the chilled cake from the freezer to apply the final layer of frosting on the top and sides of the cake. Use a cake scraper tool to smooth out the frosting.
Gently press sprinkles onto the bottom border of the cake, if desired. Use a piping bag fitted with a small star tip to pipe swirls around the top edge of the cake, and top with more sprinkles, if desired.
Sprinkles

Notes

*You can also use vanilla or yellow cake mix in this recipe.

**If you don’t have buttermilk, you can measure out 1½ cups of milk, remove 1½ tablespoons, and add 1½ tablespoons of white vinegar or lemon juice. Mix well and let stand for 5 minutes before using.

***In place of the sour cream, you can use plain Greek yogurt.

****For this bright color, I used the brand Chefmaster Liqua-gel in the color Lemon Yellow.

Becky's Top Tips:

Bring all ingredients to room temperature for the best results.
For a pure white cake, swap the 3 eggs for 5 egg yolks.
Measure the flour using the spoon-and-level method to avoid a dry cake.
Do not overmix the batter; otherwise, your cakes may come out tough.
Chill the cakes thoroughly for the most even frosting application.
If the frosting is too stiff after 5 minutes of whipping, add 1 tbsp of heavy cream to soften.
Add a layer of lemon curd between the layers for even more lemon flavor. Simply pipe a dam of buttercream around the edges, then fill with curd before stacking on the next layer.
Crumb-coat the cake before frosting to catch any crumbs for a smoother appearance.

Make-Ahead: You can bake the cakes up to 1 day ahead and store them in the fridge until ready to frost.

Storage: Store lemon cake in an airtight container at room temperature for up to 2 days, in the refrigerator for up to 4 days, or in the freezer for up to 1 month.

Nutrition