Blueberry and Lime Cake
Prep time
Cook time
Total time
This blueberry and lime cake is light, bright, and perfect for spring.
Serves: 1 2-layer cake
For the cake:
  • 2 ¼ cups all purpose flour
  • 2 ¼ teaspoon baking powder
  • ¾ teaspoon salt
  • ¾ cup unsalted butter, at room temperature
  • 1 ½ cups sugar
  • Zest of 2 limes
  • 3 large eggs, at room temperature
  • 1 teaspoon vanilla
  • ½ cup sour cream
  • ¼ cup fresh lime juice
  • 1 cup frozen blueberries, plus 1 teaspoon flour
For the lime buttercream frosting:
  • 6 large egg whites
  • 1½ cups granulated sugar
  • 2½ cups unsalted butter room temperature, cut int 1 tablespoon pieces
  • ¼ cup fresh lime juice
For the cake:
  1. Preheat the oven to 350°F. Butter two 8" cake pans, line them with parchment paper, and butter the parchment paper.
  2. Add the sugar to a small mixing bowl. Add the lime zest and rub the zest into the sugar, until the sugar is fragrant. In a medium bowl, whisk together the flour, baking powder, and salt.
  3. In a large mixing bowl with a handheld mixer, or in a stand mixer fitted with the paddle attachment, cream the butter at medium-high speed until light and fluffy, about 2 minutes. Add the sugar and lime zest and beat for 2 minutes more, until combined.
  4. Add the eggs one at a time, beating for a minute between each addition.
  5. Add half of the dry ingredients and mix on low speed until just incorporated, followed by the sour cream and lime juice, then the rest of the dry ingredients. Be careful not to overmix.
  6. In a separate bowl, add the frozen blueberries and 1 teaspoon of flour and mix them together. Add this into the cake batter and mix by hand.
  7. Pour the batter as evenly as you can between the two cake pans. The batter will be thick, so use a rubber spatula to smooth out the top as evenly as you can.
  8. Bake for 30-35 minutes, or until a toothpick inserted into the middle of the cake comes out clean. Allow the cakes to cool in the pan for a few minutes before turning them out onto cooling racks. Allow the cakes to cool completely before frosting.
For the lime buttercream frosting:
  1. Set a small saucepan of water over medium heat and bring to a simmer. Place the egg whites and sugar in a large heatproof bowl and whisk them together.
  2. Place the bowl over the simmering water. Whisk the mixture continuously, until it is smooth and reaches 160°F on a candy thermometer. This could take up to 10 minutes.
  3. Remove the bowl from the heat and whisk using a handheld mixer on medium-high speed until the mixture is close to room temperature and has the consistency of shaving cream. This will take 5-10 minutes.
  4. Add the butter 1 tablespoon at a time, mixing constantly. As you add more butter, the mixture might start to look curdled, but keep adding and mixing until it becomes smooth. Add in the lime juice and mix to combine.
To assemble the cake:
  1. Place one of the cake layers on a cake stand. Spread 1 cup of the buttercream frosting on top using an offset spatula. Place the second cake layer on top.
  2. To make the ombre effect, divide the remaining frosting into three parts. One of the parts should have twice as much as the other two (this will be for the lightest color, which you will also use on the top of the cake). Add a drop of green food coloring to the largest portion, then a little more to the next, and a little more to the next, so you end up with three varying shades of green.
  3. Place couplers in 3 pastry bags. Fill each with a different shade of frosting. Fit the darkest shade with a petal tip (I used a Wilton 104) and pipe a wide line of frosting around the bottom of the cake. Repeat with another line.
  4. Take the middle shade and pipe two thick lines above that, followed by the lightest shade with two more lines. Use an offset spatula or a bench scraper to smooth around the outside of the cake.
  5. Place the rest of the lightest shade of frosting on top of the cake and smooth it with the offset spatula.
  6. Garnish the cake with blueberries and lime slices, if desired.
Recipe by Today We Bake at