Preheat the oven to 350 degrees F. Grease and line two 9 inch cake pans with parchment paper.

Add the poppy seeds to a food processor and blend until it resembles wet sand and smells aromatic. Alternatively, you could use a blender or immersion blender. Set aside.

In the bowl of a stand mixer fitted with a paddle attachment, add the sugar and lemon zest. Rub them together with your fingers until it resembles wet sand and smells aromatic.

To the sugar, mix in the flour, baking powder, and salt.

Cut up the butter into small cubes and add to the dry ingredients. Mix on low speed until it resembles wet sand.

Add the oil, whole milk, yogurt, eggs, and vanilla, and mix until fully combined.

Pour ¼ of the batter into a separate small bowl, then fold in the poppy seeds until evenly distributed.

Use cookie scoops to alternate the two batters between each pan, adding an equal number of scoops to each. Use a knife to swirl the batters together, then gently shake the pans to encourage them to spread out into an even layer.

Bake the cakes for about 25-30 minutes or until the cakes start to pull away from the sides of the pans. Immediately turn the cakes out onto a wire rack to cool completely.

Once cool, wrap the cakes in plastic wrap and freeze until ready to decorate. Frozen cake layers will be much easier to frost!

In a medium bowl, whisk together the egg yolks, sugar, cornstarch, and salt until smooth and light in color. Then, mix in the lemon juice until fully combined.

In a medium saucepan over low-medium heat, melt the butter.

Pour in the egg yolk, lemon juice mixture, then turn the heat up to medium, and mix constantly with a rubber spatula for 3-4 minutes or until thickened and large bubbles form in the center. Immediately remove from heat.

Pour the lemon curd through a fine mesh sieve into a bowl. Transfer to a jar and chill for at least 1 hour or overnight.

Make the pastry cream: In a small saucepan over low-medium heat, bring the milk to a simmer or about 190 degrees F.

In a medium bowl, whisk together the egg yolks, sugar, cornstarch, and salt until the mixture is light in color and flows off the whisk.

Once the milk has reached a simmer, slowly pour half into the egg yolk mixture while whisking simultaneously.

Pour everything back into the saucepan and place over medium heat. Stir constantly with a rubber spatula until it begins to thicken. Once the foam on the surface disappears and large bubbles form in the center, continue stirring for one more minute, then remove from heat.

Immediately pour the pastry cream through a fine mesh sieve into a small bowl.

Place in the fridge for about one hour, stirring every 15 minutes or so until it’s room temperature.

Make the buttercream: In the bowl of a stand mixer fitted with the paddle attachment, cream together the butter and cream cheese on low speed until smooth.

Add the pastry cream and vanilla bean paste and mix until fully combined.

Place the first cake layer on a cake stand. Pipe a dam of buttercream around the edge of the cake. Fill the center with an even layer of lemon curd.

Add the second cake layer and top with a few scoops of buttercream. Use an offset spatula to smooth out the top, and spread the excess all over the sides.

Continue decorating the cake as desired. Top with poppy seeds and lemon zest, and enjoy!