Blueberry Swirl Cake with Lemon Curd Macarons

Ingredients

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)

For the lemon curd:

1. 170g (about 4/5 cup) sugar
2. 100ml (about 1/3 cup + 1 tbsp) freshly squeezed lemon juice
3. 4 tsp finely grated lemon zest
4. 5 large egg yolks (save the egg whites for the macarons)100g (about 1 stick minus 1 tbsp) butter, cubed

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

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

Instructions

For the lemon blueberry cake:

1. Preheat oven to 180°C (350°F) and grease and line three 15cm (6″) or 18cm (7″) round cake pans (slightly thinner layers).
2. In a medium mixing basin, sift together the flour, baking powder, and salt. Combine the lemon juice and milk in a jug.
3. In a large mixing basin, combine the butter and 1.5 cups sugar and beat on high speed with an electric mixer for at least 5 minutes, or until pale and fluffy.
4. Reduce to medium-low speed and beat in the egg, milk, lemon juice, and lemon zest. Reduce the speed to low and gently include the flour mixture until it is completely mixed.
5. Gently fold in the blueberries until they are uniformly distributed.
6. Split the batter evenly among the three prepared muffin pans and level the tops with a spatula.
7. Preheat the oven to 350°F and bake the cakes for 10 minutes. Reduce the temperature of the oven to 160 degrees Fahrenheit. Bake for 40-50 minutes, or until golden brown and firm to the touch, and a skewer put into the center of the cake comes out clean, depending on the size of your pan (if on top and bottom rack, switch cakes between racks halfway through, baking). Allow to cool in the tin on a wire rack before turning out. Before frosting, refrigerate in an airtight jar for up to a day.

For the lemon curd:

1. In a small saucepan over medium heat, stir the sugar, lemon juice, and zest until the sugar dissolves.
2. In a heatproof bowl, whisk together the egg yolks and gradually add the hot lemon mixture. Using a fine-mesh strainer, strain the mixture.
3. Return to the heatproof bowl and set it over a pot of hot water to keep it warm. Cook until the mixture coats the back of a wooden spoon, stirring constantly. Allow the mixture to simmer but not boil. It’s critical to cook this for a long enough time, or the curd would be too runny for your macarons and cake.
4. Remove the pan from the heat and toss in the butter cubes one at a time until completely mixed.
5. Cover the surface of the mixture with clingfilm and chill for at least 30 minutes to allow it to solidify.

For the macarons:

1. Blend the almond meal, icing sugar, and egg whites in a food processor until a fine paste forms. Remove from the equation.
2. Place the caster sugar in a saucepan to make the Italian meringue. Make sure the sugar is moistened before adding the water. Bring the mixture to a boil over high heat (do not stir). Using a candy thermometer, measure the temperature of the syrup at 118°C (245°F).
3. While the sugar is heating, use a stand mixer fitted with a whisk attachment to beat the egg whites and egg white powder at medium speed until the eggs turn frothy. Continue to beat at a high speed until stiff peaks appear.
4. Once the syrup reaches 118°C (245°F), remove it from the heat and allow the bubbles to decrease for a few seconds. While whisking at medium speed, drizzle the syrup over the beaten egg whites in a thin, continuous stream.
5. Continue to whip until glossy and the meringue has cooled to room temperature after all of the syrup has been added (add food coloring here) (around 10 to 15 minutes).
6. Fold a third of the Italian meringue into the almond mixture with a silicone spatula to loosen it. Fold in the remainder of the Italian meringue after that. (Use your spatula to spread the mixture over the bottom and sides of the bowl to remove any big bubbles.) Continue folding and swirling until the batter is glossy and fluid. Avoid overmixing; the mixture should flow like lava, and a stripe of mixture distributed over the surface of the remainder of the mixture should vanish after about 30 seconds.
7. Fill a piping bag with the mixture and a 1cm round pipe tip. Pipe 3cm wide circles on your prepared trays, allowing roughly 3cm between each one. To remove any huge bubbles, tap baking trays carefully and firmly on the tabletop a couple of times.
8. Allow for 60 minutes of drying time, or until the surface of one does not break or cling to your finger when gently pressed. This will assist to avoid cracking and the formation of feet 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, depending on your oven) For optimal heat distribution, set the tray of piped shells on top of an upside-down roasting sheet or another baking tray.
10. Preheat oven to 350°F and bake for 15-20 minutes. Carefully remove one of the shells to see whether the base is ready; if it is still soft and adhering to the baking paper, it needs to bake for a few more minutes.
11. Remove from the oven and cool for a few minutes on the tray before carefully removing off the sheet and cooling on a wire rack.
12. Sandwich the shells with the set lemon curd once they’ve cooled fully (recipe above).

For the icing

1. Remove the butter from the fridge 30 minutes before you begin to make the icing and cut it into small pieces. With an electric mixer, whip butter until creamy and fluffy in a large mixing bowl.
2. Reduce the speed to medium-low and gradually add the icing sugar until mixed, then add the lemon juice and beat until very pale and fluffy.
3. If your mixture is too liquid, you may need to add more icing sugar; if it is too stiff, you may need to add more lemon juice or milk (if it is already sour enough). The frosting should be silky smooth and easy to spread, yet firm enough to keep its shape.
4. 3/4 of the frosting should be placed in a separate bowl and left aside. Add roughly 1 tbsp blueberry jam or topping and 1/3 cup icing sugar to the remaining 1/2 cup icing and beat again with an electric mixer to incorporate (you may modify the amount of jam/icing sugar to taste here).
5. To build the cake, gently trim the tops of the cake with a long shape knife (ideally serrated) to ensure they are level. Before assembling your cake layers, turn them upside down.
6. Place one layer of the cake on a cake stand and spread a thick layer of lemon curd over the top using an offset spatula. Continue with the remaining cakes and additional lemon curd.
7. Crumb cover the cake with some basic lemon icing and refrigerate for around 30 minutes.
8. Alternately swirl blobs of plain white icing and blueberry icing over the surface of the cake using an offset spatula. Chill the cake before adding the macarons and blueberries to allow the frosting to set.
9. Allow at least 30 minutes for the cake to come back to room temperature before serving. For many days in the fridge, keep in an airtight container.

Source: Raspberri Cupcakes

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