Pink Lemonade Cake

Ingredients:

Lemon cake

• 0.5 cup vegetable oil + extra to grease the pans
• 2 and 3/4 cups all-purpose flour, plus extra for dusting the pans
• 2 tablespoons cornstarch
• 2 tsp baking powder
• 1/4 teaspoon of baking soda
• 1 teaspoon coarse salt
• 1.5 cups whole milk at room temperature
• 1 tbsp vanilla extract
• 0.5 cups (110 g) unsalted butter at room temperature
• Finely grated zest and juice of 2 lemons (about 2 tablespoons zest and 1/3 cup juice)
• 1 and 2/3 cups sugar
• 4 large eggs at room temperature
• Pink gel food coloring

Glaze

• Very pure whites of 3 eggs, room temperature
• 1.5 cups of sugar
• 1 tbsp light corn syrup
• 2 tsp vanilla extract
• 0.5 tsp cream of tartar
• 1/4 teaspoon coarse salt
• 1 tbsp. freshly squeezed lemon juice
• Pink gel food coloring
• Special equipment: 4 round cake pans with a diameter of 22 cm; small pastry knife

Preparation:

1. Place baking sheets in the upper and lower thirds of the oven and preheat to 350°F (175°C). Grease the bottoms and sides of four 9-inch (22 cm) round cake pans with vegetable oil. Dust with flour and shake out any excess; set aside.
2. Cakes:
   
   In a medium bowl, combine the flour, cornstarch, baking powder, baking soda, and salt. Combine the milk and vanilla in a large liquid measuring cup. Set everything aside.
3. In a large bowl, beat the butter, lemon zest and juice, vegetable oil, and sugar with a mixer on medium-high speed until light and fluffy, 5 to 7 minutes, stopping occasionally to scrape down the sides with a spatula. Beat in the eggs one at a time until fully incorporated, then continue beating at medium-high speed until the mixture is thick, smooth, and glossy, about 3 more minutes. Reduce the speed to medium-low and add a third of the flour mixture, mixing until fully incorporated. Beat in half of the milk mixture until smooth. Repeat the alternation, adding the last third of the flour mixture and mixing until smooth. Stir several times with a spatula.
4. Divide the batter evenly among 4 medium bowls. Tint one portion with 1 drop of pink food coloring, another with 2 drops of food coloring, a third with 1 teaspoon of food coloring, and the last with 1/4 teaspoon of food coloring. Stir in each bowl until streaks are gone; the batter should gradually turn lighter shades of pink.
5. Pour each color of batter into one of the prepared pans. Bake until the top is golden brown, the edges of the cakes begin to pull away from the sides of the pan, and the center springs back when lightly pressed, about 30 minutes. Let cool in the pans for 10–15 minutes, then turn the cakes out onto a wire rack to cool completely.
6. Glaze:
   
   Fill a medium saucepan about a third full with water and bring to a boil over medium-high heat. Combine the egg whites, sugar, 1/4 cup water, corn syrup, vanilla, cream of tartar, and salt in a large (preferably glass or metal; see Note) heatproof bowl that sits on top of the saucepan, making sure it doesn't touch the water.
7. Place the bowl over the saucepan and beat with a mixer on low speed until the sugar dissolves and the mixture begins to thicken, 1–2 minutes. If the mixture begins to crystallize on the sides of the bowl, brush the bowl with a damp pastry brush.
8. Increase mixer speed to medium-high and continue beating until stiff, glossy peaks form, about 7 minutes. Remove from heat and continue beating until the mixture cools slightly, about 30 more seconds. Stir in lemon juice and 2 drops of pink food coloring. The glaze will set as it cools.
9. While the frosting is still slightly warm, begin assembling the cake. Place the brightest pink cake layer (tinted with 1 teaspoon food coloring) on ​​a cake stand or serving platter. Spread 0.5 cup frosting evenly over it. Then place the second-brightest pink cake layer (tinted with 1/4 teaspoon food coloring) and add another 0.5 cup frosting.
10. Layer the third-best colored cake layer (2 drops of food coloring) and another layer of 0.5 cups of frosting. Top with a light pink cake layer (1 drop of food coloring). Spread the remaining frosting over the sides and top of the cake, making swirls in the frosting with a spatula. Do not refrigerate; the frosting will set after it has cooled completely, in about 30 minutes.
    
    
    Note
    
    To ensure the icing whips properly, make sure there are no traces of yolk in the egg whites; break each egg white into a separate bowl before adding it to the bowl with the others. Also, make sure the bowl is clean and grease-free. We recommend using glass or metal rather than plastic.
    
    The cake layers can be baked up to a day ahead. Let them cool completely, then wrap tightly in plastic wrap and foil. Store at room temperature.