Mojito Cake

Mojito Cake has two layers of fluffy white cake, flavored with rum and fresh lime. The cake is filled with fresh lime curd, brushed with a mint simple syrup, and frosted in a whipped vanilla rum buttercream frosting. This unique cake is full of flavor!

Course Dessert

Cuisine Dessert

Keyword Layer Cakes, White Cake, Rum Cake, Lime Cake

Prep Time 1

Cook Time 27

Servings to 16 slices

Calories 1303kcal

Author Stephanie Simmons

Ingredients

For the Lime Curd

5 large egg yolks reserve the whites for the cake
2 large eggs
3/4 cup + 2 tbsp granulated sugar
1 large lime, zested
3/4 cup fresh lime juice about 6 large limes
1/2 tsp vanilla
pinch of salt
6 tbsp salted butter, cubed

For the Mint Simple Syrup

1/4 cup granulated sugar
1/4 cup water
1 large handful fresh mint leaves

For the Cake Layers

2 and 1/3 cups cake flour, spooned & leveled 255 grams
2 tsp baking powder
1/2 tsp baking soda
1/2 tsp salt
7 tbsp salted butter, softened at room temperature
1/3 cup vegetable oil
1 and 3/4 cup granulated sugar
5 large egg whites, at room temperature
1/2 cup sour cream, at room temperature
1 tbsp vanilla extract
1/2 cup milk, at room temperature I used 2%
1/4 cup + 2 tbsp spiced rum
1 large lime, zested
2 tbsp fresh lime juice

For the Vanilla Rum Whipped Frosting

1 cup + 6 tbsp salted butter, at room temperature 22 tbsp, or 310 grams
5 and 3/4 cups to 6 cups powdered sugar
1 tbsp vanilla extract
1-2 tbsp mint simple syrup
3-4 tbsp spiced rum
4 ounces cream cheese, softened at room temperature & cubed Use the full-fat block kind

For Serving

fresh lime slices, lime zest, and mint leaves

Instructions

Make the Lime Curd: Place a strainer over a medium bowl. Add egg yolks, eggs, and sugar to a medium saucepan. Whisk until well combined. Whisk in the lime juice, lime zest, and salt. Cook, whisking constantly, over medium heat, for 4-5 minutes or until the temperature on a candy thermometer reaches 185° F. The mixture should coat the back of a spoon, and hold a trail when you drag your finger through the curd. Remove the saucepan from the heat immediately at this point, and strain it into the medium bowl. Whisk the butter into the hot curd mixture, a few tablespoons at a time, until fully combined. Whisk in the vanilla. Press plastic wrap onto the surface of the curd and chill in the fridge at least 3 hours or up to 1 week before using.
Tip: Use a bit of green food coloring to make this look more like lime - it is naturally more yellow.
Make the Mint Simple Syrup: Add sugar and water to a small pot on the stove, along with the handful of mint leaves. Bring to a boil over medium high heat, then reduce heat to low, and whisk constantly until sugar is dissolved. Remove from the heat and allow the mint leaves to steep for 20-30 minutes. Strain out the mint leaves and pop the simple syrup in the fridge until ready to use.
Make-Ahead Tip: This can be made up to 1 week ahead.
Prep: Make sure all your ingredients have come to room temperature as indicated. Preheat your oven to 350° F. Prepare two 9-inch round cake tins. Rub shortening all over the inside of each pan with a paper towel, coating each evenly and completely. Cut a round of parchment paper to fit inside each (tracing is the easiest way). Place this on top of the greased pan bottom, then grease over the parchment paper. Add a handful of flour, and tap the pan around to evenly coat the entire inside with flour, tapping out the excess.
Make the Cake Batter: In a medium bowl, whisk together the dry ingredients – flour, baking powder, baking soda, and salt. In a large bowl with an electric mixer, cream the softened butter for about 30 seconds, until creamy. Add the vegetable oil and cream together with the butter for 1 minute. Add the sugar and beat on high speed for 2 full minutes. The mixture will be fluffy. Add the egg whites, two at a time and then the last one on its own, beating on medium high speed between each addition for 45 seconds.
Add the sour cream, vanilla, and lime zest and mix in on medium low speed until just combined.Slowly pour in the dry ingredients while the mixer runs on low speed. Mix just until the last streaks of flour are disappearing into the batter, then turn off the mixer and use a spatula to make sure everything is folded in. Finally, slowly pour in the milk, rum, and lime juice while the mixer runs on low speed. Mix until just combined – don't over mix!
Bake: Pour batter evenly into your prepared tins. (You can eyeball this or use a kitchen scale to help with precision.)
Bake the cakes for 21-26 minutes. A toothpick inserted into the center will pull out moist crumbs and the cakes shouldn't jiggle in the center when you move the pan. Let cakes cool in the pans on a wire rack for 10 minutes. (If the centers dip a bit, that's normal with this cake.)
Then, invert onto cooling racks to cool completely before frosting and assembling.
Make the Vanilla Rum Frosting: In a large mixing bowl, cream the butter. Add powdered sugar in 3 additions, mixing on medium speed between each, until smooth. Add the remaining ingredients, and mix. Beat in the cream cheese last - this will prevent weepy frosting. Taste and adjust as desired.
Assemble & Frost the Cake: Brush each cake layer with mint simple syrup, using a pastry brush. Place the first cake layer on a cake stand protected with wax paper strips, or a turntable. (A turntable is the easiest!) Top the layer with 1 generous cup of frosting, spreading it evenly with an offset spatula. Pipe a border around the cake, and add 1/3 cup of lime curd inside the ring, spreading it evenly with an offset spatula. Place the second cake layer on, and pop in the fridge to chill for 5-10 minutes so nothing will slide around. Add a thin layer of frosting over the top and sides of the cake. Use a cake scraper to smooth out and remove excess frosting. This is your crumb coat, so don't fret if it isn't perfect. Pop the cake in the fridge for 30 minutes or until the frosting is set. Then, use the remaining frosting to frost the cake, using the cake scraper to smooth the top and sides.Chill the entire cake in the fridge for 30 minutes, or until the frosting is set before covering (with plastic wrap or a cake lid) or serving.
Tip: If your frosting is getting too soft at any point from sitting out, pop it back in the fridge for a bit to firm back up. If it gets a bit too firm in the fridge, beat it with your mixer to make it spreadable again.
Serve + Store: Once the fully assembled cake has chilled for at least 30 minutes, decorate with lime wedges and mint, then slice and serve! You can also keep the fully assembled cake in the fridge overnight before serving. Store leftovers in an airtight container in the fridge, and let come to room temp a bit before serving, as the frosting will become quite solid. Leftovers keep in the fridge for 3-4 days.

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