Blueberry Swirl Cake with Lemon Curd Macarons

My life is finally starting to return back to my regular routines. Weddings are hectic. And it wasn't even my wedding! Luckily for me, there was a long weekend the week after, which allowed me to rest up and get back my baking groove. So I made cake. And macarons. And lemon curd. And blueberry sauce! I love long weekends.

I'm in love with the swirly mess of icing on this cake. It's an easy way to pretty up a cake that doesn't require any precision or perfection, that's what I love about a messy finish on a cake. All I did was mix a little bit of blueberry jam into some of my regular lemon butter icing and swirled a few dollops of the icing on the cake. I was hoping for it to give the icing a purple tint, but it came out more of a deep pink. Still pretty! I love how it looks like the cake is covered in big pink rose petals.

The cake inside is a blueberry lemon cake, sandwiched together with some lemon curd. I had a ton of lemons in the fridge and blueberries were on special so these were easy choices. I stupidly didn't follow my own recipe instructions and forgot to turn the temperature down on my cake so the edges browned a lot more than they should have and dried the cake out too much, but luckily the curd, blueberies and icing helped to take away some of that dryness. I was a little too timid with the amount of lemon curd on the bottom layer, but other than that I'm really pleased with how the cake turned out.

As I've mentioned in recent macaron posts, I'm having a horrible time with hollow shells when I bake macarons in my new oven. I've tried so many different tweaks, which have only slightly improved them but not eradicated those darned air pockets entirely. I have always used the French method for my macarons since I have a huge aversion to dealing with hot sugar syrup, but I finally worked up the energy to switch over to the Italian meringue method that Trissalicious, and many other bakers use. I know from the few times I've used it that it results in a much smoother shell and is more forgiving to the little mistakes that the French method exposes. And I have a Kitchenaid stand mixer, and a sugar thermometer, so my only excuse for avoiding it now is laziness. No more! The result were these picture perfect macarons, without an air pocket in sight! I undermixed the batter slightly, so the texture was more fluffy than I would have preferred, but much better than a crunchy, hollow shell. Feel free to keep using my old French method recipe if it's working successfully for you, but I think from now on I'm gonna stick with the Italian method to save me from hollow shell hell.

Blueberry Swirl Cake with Lemon Curd Macarons

(makes a 3 layer 6 inch (or thinner 7 inch) cake, macaron recipe from Trissalicious) 

For the lemon blueberry cake:

170g (1.5 sticks) butter, softened

3 cups (about 420g) plain/all-purpose flour

3 tsp baking powder

1/2 tsp salt (if using unsalted butter, add an extra 1/2 tsp)

1 1/2 cups (300g) sugar

2 eggs, room temperature

3/4 cup milk

1/4 cup lemon juice + 1 tbsp finely grated lemon zest

300g (10.5oz/about 2 punnets) fresh or frozen blueberries (I used frozen)

1. Grease and line three 15cm (6") or 18cm (7", will result in slightly thinner layers) round cake tins and preheat oven to 180°C (350°F). 
2. Sift flour, baking powder, and salt together into a medium bowl. Place lemon juice and milk in a jug together.
3. Place butter and 1.5 cups sugar in a large mixing bowl and beat with an electic mixer on high speed until pale and fluffy, at least 5 minutes. 
4. Reduce speed to medium-low; mix in egg, milk, lemon juice and lemon zest. Reduce speed to low; gradually mix in flour mixture until just combined.
5. Fold in blueberries gently until evenly distributed.
6. Split mixture between the three prepared tins and smooth tops with a spatula.
7. Bake cakes for 10 minutes. Reduce oven temperature to 160 degrees. Bake until cakes are golden brown and firm to the touch, and a skewer inserted into the centre of the cake comes out clean, about 40-50 mins but timing will vary depending on your tin size (if on top and bottom rack, switch cakes between racks halfway through, baking). Let cool in tin on a wire rack, then turn out. Can be stored in an airtight container for a day or so before icing. 

For the lemon curd:
170g (about 4/5 cup) sugar
100ml (about 1/3 cup + 1 tbsp) freshly squeezed lemon juice
4 tsp finely grated lemon zest
5 large egg yolks (save the egg whites for the macarons)

100g (about 1 stick minus 1 tbsp) butter, cubed

1. Stir the sugar, lemon juice and zest in a small saucepan over medium heat until the sugar dissolves.
2. Beat the egg yolks in a heatproof bowl and gradually add the hot lemon mixture. Strain the mixture through a fine-mesh sieve.  
3. Return to the heatproof bowl and place over a saucepan of simmering water. Cook, stirring continuously, until the mixture coats the back of a wooden spoon. Do not allow the mixture to boil. It is important to ensure this cooks for long enough or curd will be too runny for your macarons and cake.
4. Remove from the heat and add the butter cubes, one at a time, stirring until fully combined. 
5. Cover surface of mixture with clingfilm and refrigerate to allow it to set, at least 30 mins.

For the macarons:

Note: this method uses an Italian meringue. If you prefer, you can continue to use the French method I normally use. If you are a beginner with macarons read up and practice plain macarons first. BraveTart has lots of useful advice and info on the subject

Almond Meal Paste:

125 grams almond meal

125 grams icing/confectioner's sugar

50 grams egg whites

Italian Meringue:

125g caster (granulated) sugar

35g water

50grams egg whites

Pinch of egg white powder

Optional: powdered/gel food colouring

1. In a food processor, blend the almond meal, icing sugar and egg whites until this resembles a fine paste. Set aside.
2. To make the Italian meringue, place the caster sugar in a saucepan.  Add the water and make sure that the sugar is dampened.  Heat the mixture and bring this to a boil (do not stir).  Place a candy thermometer in the syrup and take the temperature of 118°C (245°F)
3. While the sugar is cooking, beat the egg whites and egg white powder using a stand mixer fitted with a whisk attachment and beat at medium speed until the eggs become foamy. Continue beating on high until stiff peaks form.
4. Stop the syrup from cooking once it reaches 118°C (245°F) and take this off the heat and let the bubbling subside for a few seconds.  Pour the syrup in a thin, steady stream over the beaten egg whites while the continuing to whisk at medium speed.
5. When all the syrup has been added, (add food colouring here) continue to beat until glossy and meringue has cooled to room temperature (around 10 to 15 minutes).
6. Using a silicone spatula, fold a third of Italian meringue into the almond mixture to loosen it.  Then, fold in the rest of the Italian meringue.  (You really want to beat all the large bubbles out of the mixture, which is easily done by smearing the mixture on the bottom and side of the bowl with your spatula) Continue folding and stirring until the batter is glossy, and fluid. Take care not to overmix, the mixture should flow like lava and a streak of mixture spread over the surface of the rest of the mixture should disappear after about 30 seconds. 
7. Place mixture in a piping bag with a 1cm round piping tip. Pipe circles about 3cm wide on your prepared trays, leaving about 3cm space around each one. Tap baking trays carefully and firmly on the benchtop a couple times to remove any large bubbles.
8. Leave to dry for about 60 mins, until when you press the surface of one gently it does not break/stick to your finger. This will help prevent any cracking and help the feet to form on the macs.
9. Preheat your oven to 130-150°C (265-300°F), depending on your oven (fan-forced ovens may need to be set as low as 100°C, it really depends) . You can place the tray of piped shells on top of an upside-down roasting tray or another baking tray, for better heat distribution.
10. Bake for 15-20 minutes. Carefully test if the base of the shell is ready by gently lifting one and if it’s still soft and sticking to the baking paper, then it needs to bake for a few minutes longer. 
11. Remove from the oven and cool on the tray for a few minutes, then gently remove from the sheet and place on a wire rack to cool. 
12. When completely cool, sandwich shells with set lemon curd (recipe above).

For the icing:

300g (about 2 & 2/3 sticks) butter

500g (about 4 cups) icing/confectioner's sugar, sifted

3-4 tbsp lemon juice, adjusted to taste and texture

To mix: blueberry jam, or this blueberry topping (strained) + 1/3 cup (about 40g) icing sugar, sifted

Optional: fresh blueberries and lemon curd macarons to decorate

1. Prepare the icing; remove butter from fridge 30 mins before starting and chop into small cubes. In a large mixing bowl, beat butter on high with an electric mixer until smooth and fluffy. 
2. Reduce speed to medium-low and gradually add icing sugar until combined, add lemon juice then increase speed to high and beat until very pale and fluffy. 
3. You may need to add more icing sugar if your mixture is too runny, if mixture is too stiff you can add more lemon juice or milk (if it is already sour enough). The icing should be smooth and easily spreadable, but stiff enough to hold its shape.
4. Place 3/4 of the icing in a separate bowl and set aside. With the remaining 1/2 of icing add about 1 tbsp blueberry jam or topping and 1/3 cup icing sugar and beat again with an electric mixer to combine (you can adjust the amount of jam/icing sugar to taste here).
5. To assemble cake; use a long shape knife (preferably serrated) to carefully trim the tops of the cake to ensure they are level. Flip your cake layers upside down before assembling.
6. Place one layer on your cake stand and use an offset spatula to spread a thick layer of lemon curd over the top of the cake. Repeat with remaining cakes and more lemon curd.
7. Crumb coat cake with some of the plain lemon icing and then chill for about half an hour.
8. Using an offset spatula, alternately swirl blobs of plain white icing and blueberry icing over the surface of the cake. Top cake with macarons and blueberries and chill to allow icing to set.
9. Remove from the fridge at least 30 mins before serving to allow cake to come back to room temperature. Can be stored in the fridge in an airtight container for several days.