1 box white cake mix
3 large eggs
1/2 cup vegetable oil
1 cup water
1 1/2 cups blueberries, divided, plus more for garnish
8 ounces almond flour or very finely ground almonds
2 1/2 cups powdered sugar
1/2 cup plus 2 tablespoons granulated sugar
1/2 cup water
3/4 cup egg whites (from 6 to 7 large eggs), room temperature
1/4 teaspoon fine sea salt
5 drops bright purple food coloring
2 drops dark blue food coloring
1 tablespoon lemon zest
3/4 cup lemon juice
3/4 cup sugar
1/4 teaspoon salt
3 large eggs plus 4 large egg yolks
4 tablespoons butter
2 cups whipping cream
1/4 cup sugar
1 teaspoon vanilla
Preheat oven to 350 degrees.
In a large mixing bowl, combine cake mix, eggs, oil and water. Divide batter between two 8-inch springform pans. Scatter half of the blueberries into each pan and lightly incorporate. Bake for 20 minutes.
In a food processor, pulse almond flour and powdered sugar. Sift mixture through a fine mesh sieve, discarding any large pieces.
In a small saucepan, heat the granulated sugar and water until it reaches 240 degrees and is simmering.
In a large metal mixing bowl, whisk egg whites and salt until slightly frothy. With the mixer running on low, slowly add the sugar syrup and whip until firm shiny peaks form, 5 to 8 minutes. Whip in food coloring. Fold the almond mixture into egg whites, one-third at a time, until just combined.
Transfer mixture to a piping bag fitted with a 1/2 inch round tip. Pipe in a circular motion starting from the outside edges of the pans and working your way to the center.
Preheat the oven to 300 degrees. Bake for 25 minutes or until macarons has risen and is beginning to brown on the bottom.
Lower the temperature to 200 degrees and return the cakes to the oven for another 25 to 30 minutes. Allow to cool and remove from the pan.
Make lemon curd: In a medium saucepan, add lemon zest, juice, sugar and salt and bring to a simmer. In a medium bowl, whip the eggs until almost double in volume. Slowly drizzle the hot lemon mixture while whisking until fully incorporated. Return to the saucepan and whisk over medium heat until thickened. Add butter, then strain through a sieve and set aside.
In a medium bowl, whip cream, sugar and vanilla until soft peaks form. Set aside.
When cake is fully cooled, lay on a cake stand, top with lemon curd and lay the second cake on top. Garnish with more lemon curd, fresh whipped cream and blueberries.