Yesterday was my birthday! This was my 2nd birthday on lockdown, so I decided to make myself a birthday cake. Since we were celebrating both my birthday and Mother’s Day this weekend, I thought that something spring-themed in both flavour and decoration would be nice.
I wanted to make a lemon poppy seed cake and fill it with blackberry filling. I used the Cook’s Illustrated Fluffy Yellow Layer Cake as a base recipe and substituted 2/3 cup whole milk and 1/3 cup lemon juice in for the 1 cup of buttermilk in the recipe and added 2 tbsps of lemon zest as well as 1 tbsp of poppy seeds. I hoped that would give me enough lemon flavour in the cake. For the blackberry filling, I used my standard raspberry filing recipe but reduced the sugar slightly.
I wanted to frost it with lemon cream cheese frosting. The issue with cream cheese frosting is that it tends to be quite soft and I wanted to do decorative piping. I found a recipe for a crusting cream cheese frosting and decided to try that. After making the frosting, I tried a bit of it and it was way too sweet for a whole cake! I decided to save that frosting in the freezer to top cupcakes another time and instead made a Swiss meringue buttercream. I like Swiss meringue buttercream because it is much less sweet than a traditional American buttercream and it has a much smoother texture. The only drawback is that it takes a lot longer to make (30-45 minutes vs 5). To add lemon flavour to the buttercream, I added some lemon juice to the egg white and sugar mixture before cooking it and then after the buttercream was all mixed, I added another tbsp of lemon juice, some lemon extract and lemon zest.
For decoration, I decided to attempt a striped buttercream. To do this you cover the cake in one colour of buttercream then run a cake comb around the sides to remove stripes of the buttercream and create grooves. After chilling the cake, you can pipe another colour of buttercream in the groves. Then you go over the sides with a cake scraper until you expose clean-looking stripes. It’s not the easiest decorating technique because if you have any air holes in the first colour of buttercream, the second colour can bleed into it, so you have to be meticulous with the first coat of buttercream. However, it does make for a striking cake!
To finish, I combined my leftover white and coloured buttercream into a piping bag and piped some decorative two-toned rosettes and stars around one side of the cake. I thought the blank side of the top looked a bit bare, so I melted and coloured some candy melts and piped out a couple of butterflies to put on top.
Because I had to work the morning of my birthday, I made the cake the day before and I had to look at it sitting in the fridge for a whole day before I could try it! Thankfully it was worth the wait! The lemon came through in both the cake and the buttercream but wasn’t overpowering and the blackberry filling was delicious! It was my daughter’s favourite part 🙂
Here is the recipe below for you to try!
Ingredients
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For the Lemon Poppy seed Cake
- For the Blackberry Filling
- For the lemon syrup
- For the Lemon Swiss Meringue Buttercream
Instructions
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For the Lemon Poppy Seed Cake
- Adjust your oven rack to the lower-middle position and heat the oven to 350F/180C. Grease, line and flour 3 8-inch/20 cm round cake pans. If using cake strips, soak the strips in cold water.
- In a large bowl, whisk together the flour, baking powder, baking soda, salt and 300g (1 1/2 cups) sugar.
- In another medium bowl, whisk together the melted butter, milk, 6 egg yolks, lemon juice, oil, vanilla and lemon zest. The lemon juice will curdle the milk, but that is fine.
- In a large bowl, beat together the egg whites and a pinch of cream of tartar until foamy.
- With the beaters on low speed, gradually pour in the remaining 50 g (1/4 cup) sugar. Increase the speed to medium-high and whip the white until you have glossy, stiff peaks, about 2-3 minutes.
- Pour the milk mixture into the flour mixture and beat on low speed until the batter is smooth and fully incorporated, about 30 seconds. Stir in poppy seeds.
- Using a rubber spatula, stir in one-third of the whites into the batter. Then add the remaining two-thirds and gently fold until no white streaks remain.
- Divide the batter evenly between the three prepared pans and smooth the tops with a rubber spatula. Gently tap the pans on the counter to release any air bubbles. If using cake strips, place them around your pans.
- Bake until a toothpick inserted in the centre comes out clean, about 20-25 minutes.
- Let the cakes cool in the pans on wire racks for 10 minutes. Remove the cakes from the pans, discard the parchment paper and let cool completely before frosting, about 2 hours. For the Blackberry Filling
- Combine blackberries, sugar, lemon juice, a pinch of salt, and 2 tbsp (30 ml) water in a medium saucepan. Cook over medium heat until the blackberries have broken down and the mixture is cohesive, about 5 - 10 minutes. Use a spoon to mash the softened blackberries to release their juices.
- Pour the mixture into a fine-mesh metal strainer that is set over a bowl. Stir the mixture to push the blackberry juice and pulp through the strainer. Discard the seeds.
- In a small bowl, whisk together cornstarch with 2 tbsp (30 ml) water.
- Rinse out the saucepan and return it to the stove. Add strained raspberry mixture and cornstarch mixture to the saucepan. Heat over medium heat, whisking constantly until mixture is thick and jam-like, about 2-5 minutes. Pour the filling into a bowl and cover with plastic wrap. Chill in the fridge until completely cool. For the Lemon Syrup
- in a small saucepan, combine water, sugar and lemon juice. Bring it to a boil and simmer until sugar is fully dissolved. Remove from heat and cool completely. For the Lemon Swiss Meringue Buttercream
- Place egg whites, 2 tbsp lemon juice and sugar into the bowl of a stand mixer, whisk until combined.
- Place the bowl over a double boiler on the stove and whisk constantly until the mixture is hot and no longer grainy to the touch (approx. 3mins). Or registers 160F/71C on a candy thermometer.
- Place the bowl on your stand mixer and whisk on med-high until the meringue is stiff and cooled (the bowl is no longer warm to the touch and the temperature of the meringue is 69-72 F/21-22 ). This could take up to 15 minutes. If the mixture is still not cool enough after 15 minutes, chill in the fridge for 5-10 minutes until it is cool enough. It is important that the mixture is not hot, or you will end up with soupy or too soft buttercream.
- Slowly add the cubed butter, one piece at a time, and mix until smooth.
- Add remaining 1 tbsp lemon juice, the lemon extract, lemon zest and salt and beat to combine. The buttercream may be kept covered at room temperature for up to 12 hours. For Assembly
- Trim cake layers so that the tops are flat, if necessary.
- Place one cake layer on a cake board and brush the top with lemon syrup.
- Spread a thin layer of buttercream over the top of the cake and then pipe a thicker band to border the sides of the cake. Spread half of the filling inside the buttercream border. Repeat with 2nd layer of cake, lemon syrup, buttercream and filling.
- Top with 3rd layer of cake. Soak the cake with lemon syrup then top with a layer of buttercream.
- Check the layers on the sides of the cake. To hold the cake layers in place while you do the crumb coat, you can stick a skewer down through the centre of the cake. Coat the sides in a thin layer of buttercream. Chill the cake for 30 minutes until the buttercream is solid before adding your final coat of buttercream and decorating the cake.
Happy birthday!
Thanks!
Happy belated birthday. The cake is beautiful and looks delicious!