Place the rack in the center of the oven. Preheat the oven to 325°F (162°C) and line a 9” x 13” pan with a piece of parchment paper.

In a large mixing bowl with an electric hand mixer or a stand mixer with a whisk attachment, beat the eggs, sugar, lemon and vanilla extract at medium-high speed for about 2 minutes until it's thickened and a light gold color. Should your stand mixer not have a whisk attachment, then beat the mixture for 5 minutes using the paddle attachment.

Beat in the dry ingredients on low speed just until combined. Use a silicone spatula to scrape the bottom and sides of the bowl and mix briefly to incorporate.

In a small saucepan, heat the milk and lemon zest over medium heat. You shouldn't let it boil. When you see small bubbles start to appear around the edge of the saucepan, it's ready. The temperature will be 180-185°F (82-85°C). Remove the pan from the heat and stir in the butter and oil until the butter has melted.

Slowly stir the milk mixture into the batter at low speed and mix until totally combined.

Pour the batter into the prepared pan. It may look bubbly.

In a nonreactive bowl, whisk together a little of the lemon juice and cornstarch until combined. Then add the remaining juice, eggs, egg yolks, lemon zest, sugar and salt until smooth.

Place the bowl over a pan of simmering water, ensuring it doesn’t touch the water.

Continuously whisk the mixture until it thickens and reaches at least 160°F (71°C). That's the temperature most sites recommend for curd, but mine was still much too runny at this point. The photographer said that this temperature worked for her. But I had to cook mine to 175°F (79°C) to get it thick enough. The first time I made it, I cooked it to 160°F, added the butter, realized it wasn’t going to get much thicker, put it back on the heat, and thickened it up more. And it was fine.

Whisk in the butter, one tablespoon at a time, until fully incorporated.

Strain the lemon curd through a fine-mesh sieve into a clean, nonreactive bowl.

Cover the surface of the curd with plastic wrap, pressing it directly onto the surface to prevent a skin from forming, or simply stir occasionally as it cools.

Let cool until room temp, about 1 hour. You can place it in the fridge or freezer and stir occasionally if in a hurry. You can also make this 3 days in advance and keep it refrigerated. I had no issue with piping it straight from the fridge.

In a large mixing bowl using an electric or stand mixer at medium power, beat the cream cheese, sugar, vanilla and salt until totally combined.

While still mixing, now on low, gradually add the heavy cream.

Once it’s well incorporated, turn the speed to high and beat until stiff peaks form - about 3-5 minutes.

Poke holes in the cake using the handle of a large wooden spoon or whatever you have that makes sense. An apple corer is a bit too wide. My handle was 1.5 cm wide (.6"). I'd recommend doing around 40 holes (8x5).

Pipe the cooled lemon curd into the holes.

Spread the frosting over the top. It's okay if it combines with the curd a bit. If you have any curd left over, you can spread it over the top and kind of swirl it in.

Top with lemon slices/wedges and potentially some lemon peel or zest. Store covered in the fridge for up to 3 days. Bring it to room temperature before serving for the best texture and flavor.