Instructions

LEMON SOAKING SYRUP

1. In a small saucepan over medium-low heat, combine the sugar, lemon juice, water, and salt. Cook, stirring occasionally, until the sugar has completely dissolved, about 1 to 2 minutes.
2. Transfer syrup to a small heatproof bowl and refrigerate until completely cooled.
   

CAKE

1. Adjust oven rack to the lower-middle position and heat oven to 350 degrees. Spray a 12-cup Bundt pan thoroughly with nonstick baking spray and place on a rimmed baking sheet.
2. In a medium bowl, whisk together the all-purpose flour, cake flour, salt, baking powder, and baking soda. Set aside.
3. In a liquid measuring cup or medium bowl, whisk together the buttermilk, sour cream, lemon juice, vanilla extract, and lemon emulsion. Set aside.
4. In the bowl of a stand mixer fitted with the paddle attachment, combine the sugar and lemon zest. Rub the zest into the sugar with your fingertips until fragrant and evenly combined.
5. Add the butter and oil to the lemon sugar mixture and beat on medium-high speed until light and fluffy, about 3 to 5 minutes. Scrape down the sides of the bowl as needed.
6. Add the eggs and egg yolk one at a time, mixing until just combined after each addition.
7. Reduce mixer speed to low. Add the flour mixture in three additions, alternating with the buttermilk mixture in two additions, beginning and ending with the flour mixture. Mix just until combined. Remove the bowl from the mixer and gently fold the batter with a rubber spatula to ensure everything is evenly incorporated.
8. Pour batter into the prepared Bundt pan and smooth the top with a spatula. Tap the pan firmly on the counter several times to release air bubbles.
9. Bake for 50 to 60 minutes, rotating the pan halfway through baking, until a toothpick inserted into the center comes out with a few moist crumbs attached.
10. Cool cake in the pan for 10 minutes. Invert cake onto a wire rack set over parchment paper or a baking sheet. While the cake is still warm, brush the chilled syrup evenly over the cake, allowing it to absorb between applications.
11. Let cake cool completely before glazing.
    

LEMON GLAZE

1. In a medium bowl, whisk together the powdered sugar, heavy cream, lemon juice, and salt until smooth and thick. The glaze should slowly ribbon off the whisk. If needed, add additional lemon juice, 1 teaspoon at a time, until desired consistency is reached.
2. Pour the glaze over the completely cooled cake, allowing it to drip naturally down the sides. Let the glaze set for 15 to 20 minutes before slicing and serving.