Step 1

Take the butter, sour cream, and milk out of the fridge. Slice the butter into small cubes to soften quickly (see Note 2). Measure out the milk and sour cream instead of leaving them in their containers so they come to room temp more quickly.

Step 2

Arrange a rack in the middle of your oven and preheat to 350°F/175°C. Make two parchment paper rounds for two 8-inch (20 x 5 cm) round pans. Grease the bottoms of the pan with nonstick spray, then line with the parchment papers. Now spray the parchment paper round and coat the pan’s sides with nonstick spray.

Step 3

In a medium bowl, combine the flour, baking soda, baking powder, and salt. Whisk very well to evenly combine the leaveners.

Step 4

Over a large bowl, zest the 3 large lemons.

Step 5

Now stand the 3 lemons upright on a cutting board. Cut the ends off of the lemons and use a sharp knife to peel away the peel and white pith right underneath, and discard. Use your hands to peel the lemons into segments, like you would oranges. Peel away the fibrous membrane on the outside of each lemon segment. You should now be able to easily pull the lemon flesh out. Mince the lemon into tiny pieces, picking out any seeds.

Step 6

Put a strainer or sieve over a small bowl and pour the lemon pieces with accumulated juices over the strainer (do not press the lemons down to release more juice). Measure out about 70g lemon pieces (5 TBSP) and 45 mL (3 TBSP) lemon juice from the bowl. Save leftover juice for a lemon water or spritzer--don't add extra juice to the cake.

Step 7

Add the sugar to the lemon zest and rub together with your hands to release the zest’s essential oils. Now add in the softened butter and oil. Beat on low with the mixer, and once the butter is in small pieces, increase to medium . Beat until starting to get fluffy and shiny, about 1 minute total. Rinse and dry the beaters for the next step.

Step 8

Shake the can of chickpeas to disperse the starches. Pour ½ cup (120 mL) aquafaba into a small bowl. With an electric mixer (or stand mixer), beat on medium speed until the entire mixture is foamy, including at the bottom of the bowl, 1 to 1 1/2 minutes.

Step 9

To the lemon zest-sugar-butter mixture, add the whipped aquafaba, room temp milk and sour cream, and vanilla. Mix on low until just combined, 15 to 20 seconds. Finally, add the lemon pieces (if any juice has accumulated, drain it off) and the 3 tablespoons lemon juice and mix again until well combined.

Step 10

Note: before combining the dry and wet ingredients, make sure everything else is ready (oven is preheated, cake pans are prepared). This is because the baking soda will start to leaven as soon as it's mixed with the wet ingredients. Add half of the flour mix into the liquid mix, beating on low until just combined. Add the remaining flour mixture and mix just until you have a mostly smooth batter, then stop. If it gets too tough with a mixer, switch to a silicone spatula. Now use a silicone spatula to fold the bottom and sides of the bowl with the spatula to ensure it’s well combined. If the liquid has settled on the top, fold the batter a couple times to incorporate. The batter should be thick and fluffy but airy.

Step 11

Use a digital scale (or measuring cups) to evenly divide the batter between each cake pan (~ 750g / 26 oz per cake pan). Smooth out the surface with the spatula or an offset spatula.

Step 12

Bake for 33 to 35 minutes, or until the centers are set and the cakes have puffed up a bit and just started to pull away from the pans. A toothpick inserted in the center should come out clean or with a few moist crumbs but not liquid batter.

Step 13

Cool the pans on a wire rack (don't rest on the counter) for 30 minutes. Now add a sheet of parchment paper to the rack. Carefully invert the cakes onto the rack. Cool completely before assembling, ideally in the fridge for a bit to set.

Step 14

Make the Lemon Cream Cheese Frosting (or make it 1-3 days ahead of time and refrigerate). Sift the powdered sugar in a fine mesh sieve. Add the softened butter to a medium or large bowl. Using an electric mixer, beat on medium speed until smooth. Add the cream cheese and beat just until well-incorporated. Add half of the sugar and beat on low to combine. Add the remaining sugar and mix again until well-combined and fluffy, scraping down the sides with a spatula. Add the vanilla, salt, and lemon zest, and mix until smooth. If the frosting is a bit loose, refrigerate the frosting before icing the cake.

Step 15

Assemble. Place one cake (bottom side facing up) on a cake platter or large plate. Add a generous layer of Lemon Cream Cheese Frosting on top (ideally refrigerated for easier spreading), spreading to the edges using an offset or icing spatula. Top with the second cake (top side facing up). Add another layer of frosting on top and spread out. If you have leftover frosting, you can frost the sides of the cake, using the spatula or bench scraper to smooth it out. If you want less frosting, leave as is. Decorate with berries or candied lemons, if desired.