Okay…here goes nothing. I’m going to say it and then duck for cover. Ready? I love me a good boxed cake mix! There…phew. It’s out now and I feel a sense of relief. But truly, I have zero problems with cake mixes. They are fluffy, easy, and totally yummy. A few extra ingredients can take a standard run-of-the-mill cake mix and turn it into a phenomenal cake. And that’s exactly what I did with this Key Lime Pie cake.

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And So The Story Goes…

It was Saturday and I was tired. Like really tired. I had spent the previous night talking and laughing outside by the campfire and went to bed far later than what a responsible adult should but my soul needed that time of light-hearted connection.

My children, however, get up at 7 am sharp every single morning. Regardless of what time they go to bed the night before, their internal alarm clocks are as prompt as ever (insert me shaking my fist in the air.) So after only a handful of hours of sleep and a pot of coffee I was still tired. I knew what flavor of cake I wanted for Sunday Family Cake but had no desire to put forth a lot of effort…insert trusty cake mix!

How to Doctor Up A Cake Mix

I always, and I mean always, keep a box or two of white cake mixes in my pantry. I don’t even hide them, no shame in my cake mix game. I grabbed a box and tossed it in my KitchenAid. Cake mixes do tend to get a bit clumpy so I always recommend giving them a quick sift first or a minute or two in the mixer with the whisk attachment to break any of those clumps.

Now here’s where the magic happens. Don’t do what the box instructions tell you to do, grab some eggwhites, jello, greek yogurt, vanilla extract, and vegetable oil. And literally, dump it all in the mixer. Mix, pour, bake. Bam! Done! So grab that trusty cake mix (I know y’all have one) and I’ll show you how to turn it into a fabulously fast and fanciful Key Lime Pie cake.

If you love a good doctored cake mix recipe, I’ve got a few here for you to try:

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Key Lime Pie Cake

  • Author: Katie
  • Total Time: 2 Hrs 30 Mins
  • Yield: 10 Slices 1x


Fluffy lime cake layers filled with sour key lime filling and covered with the most delicious white chocolate graham cracker crumb buttercream. An easy cake recipe using a doctored cake mix that makes the perfect spring and summer treat!




  • 1 box (461 grams) white cake mix

  • 1 (85 g. package) lime jello powder

  • ½ tsp. fine sea salt

  • ¾ cup dairy-free milk, room temperature

  • ⅔ cup dairy-free yogurt, room temperature

  • ½ cup egg whites, room temperature (approx 4 egg whites)

  • ⅓ cup vegetable oil

  • 1 tbsp. vanilla extract

  • 1 tbsp. key lime juice


  • ⅛ cup granulated sugar *use ¼ cup if you prefer a sweeter filling

  • 2 tbsp. cornstarch

  • ¾ cup key lime juice

  • 1 tbsp. lemon juice

  • 1 tbsp. dairy-free salted butter

  • optional: green gel food color * I used ChefMaster


  • 1 cup dairy-free salted butter, room temperature

  • 1 cup vegetable shortening

  • 6 cups icing sugar

  • 1 cup dairy-free white chocolate chips

  • 1 cup dairy-free graham cracker crumbs

  • 1 tbsp. vanilla extract

  • 1 tsp. fine sea salt

  • optional: pink gel food color * I used ChefMaster



  1. Preheat oven to 350 degrees and prepare three 6-inch round cake pans.

  2. In the bowl of a stand mixer give the cake mix, jello powder, and salt a quick whisk to break up any clumps.

  3. Add in all the wet ingredients and mix until combined. Be careful not to overmix.

  4. Divide batter between the prepared pans and bake for 20-25 minutes or until a toothpick comes out with a few crumbs.

  5. Cool in pans for 10 minutes and then invert on a cooling rack to fully cool.


  1. In a medium pot combine sugar, cornstarch, and key lime juice and mix until smooth.

  2. Cook mixture on medium-low heat constantly stirring until mixture thickens and comes to a boil. Let boil for 1 minute and remove from heat.

  3. Add in the lemon juice, and butter and stir until melted and fully combined.

  4. If you would like a lime green color to the filing add in a tiny drop of green gel food color.

  5. Let fully cool before filling the cake.


  1. In a small microwave-safe bowl melt the white chocolate chips in 30-second intervals until fully melted and smooth. Set aside.

  2. In the bowl of a stand mixer with the paddle attachment cream the butter and shortening on high speed until light and fluffy. Approximately 10 minutes.

  3. Add the icing sugar, graham cracker crumbs, salt, and vanilla extract and mix on low until combined.

  4. While the mixer is on low, slowly pour in the melted white chocolate.

  5. Turn the mixer up to high and let mix for 5 minutes until smooth and creamy. Scrape the sides of the bowl when necessary.

  6. Add a drop of pink gel food coloring if so desired.


  1. Place one leveled layer of lime cake on a cake board or plate. Top with approximately 1 cup of buttercream.

  2. Pipe a border of buttercream around the edge and fill with approximately ⅓ cup key lime filling. Repeat with the remaining layers and apply a thin coat of buttercream all over the cake. Refrigerate for 20 minutes.

  3. Cover the cake with another layer of buttercream and smooth sides.

  4. Decorate as you please. I left the top edge raw and unfinished for a rustic aesthetic and used fresh key lime slices, graham crackers, and white chocolate chunks and shavings to decorate a top border. Enjoy.

  • Prep Time: 2 Hrs
  • Cook Time: 30 Mins
  • Category: Cakes
  • Method: Baking
  • Cuisine: American


  • Serving Size: 1 Slice
  • Calories: 998
  • Sugar: 72 Grams
  • Sodium: 397 Miligrams
  • Fat: 60 Grams
  • Saturated Fat: 39 Grams
  • Unsaturated Fat: 14 Grams
  • Trans Fat: 5 Grams
  • Carbohydrates: 89 Grams
  • Fiber: 6 Grams
  • Protein: 8 Grams
  • Cholesterol: 221 Miligrams

Keywords: baking, cake, key lime pie cake, dairy-free key lime pie cake recipe, lime cake recipe, key lime cake recipe, dairy-free key lime pie cake recipe, dairy-free lime cake recipe