Poppy Seed Cake

This recipe was originally published January 31st, 2019 under the name “the poppiest cake”. 

In most recipes, poppy seeds come in as an afterthought – a mostly lemon cake, with about a tablespoon or two of poppyseeds. I guess the poppies are added in an effort to speckle a plain yellow batter. But, what I have for you today is very different as it calls for a a lotttt of seeds so that you will not mistake this for anything but a poppy cake. Who would have known poppy seeds have such a lovely taste when given center stage? In this cake, lemon takes a backseat, allowing the seeds to shine. 

Recipe Origins

I learned the method of preparing the poppyseeds in liquid from this recipe. It’s a genius way to make it and several cakes later, I’m still not over it. I (heavily) adapted the original recipe to make a more tender cake, using buttermilk (which also gives it some tang) and cake flour. I also added lemon zest because although I tried it without it, I found the zest made all the difference between a good cake and a fantastic cake. 

Recipe Ingredients 

Buttermilk: full fat or low fat is fine. If you can’t find it, use kefir. 

Poppy seeds: We’re calling for a lot of poppy seeds for this cake and if you’re buying them from the grocery store they come in these little spice bottles that would make this quite an expensive cake. I get poppy seeds from a specialty food store that sells them in bulk for cheap. You can also find them online (try nuts.com) for about $6 a pound. 

Lemons: large lemons, rub them to remove any wax as we’ll be using the zest. 

Sugar: fine granulated sugar. 

Butter: unsalted, and at room temperature. 

Oil: any flavorless oil like avocado, grape seed or canola. 

Cake Flour: milled from a softer wheat and milled finer it gives us a very tender texture. If you don’t have it you can use all purpose but swap two tablespoons of the flour for cornstarch. 

Eggs: three whole large eggs, at room temperature. Set them in a bowl of warm water to warm up quickly. 

Vanilla: pure vanilla extract or vanilla bean paste. 

Salt: fine sea salt dissolves quicker and has a perfectly balanced flavor. If you’re using table salt, halve the amount. 

How to make Poppy Seed Cake 

Soak the seeds: stir together the buttermilk and poppy seeds in a small pot. Set the pot over low heat until the mixture is warm. Remove from heat and set aside (this allows the poppies to swell a bit and absorb some liquid)

Prep two eight inch round metal cake pans with butter and flour or a baking spray, then preheat the oven to 325. A lower temperature means the cakes will rise more evenly. 

Set the sugar in the bowl of a stand mixer and zest the lemons over it. Rub it between your fingers, then add the butter, oil, salt and vanilla 

Affix the paddle attachment and beat this until *very* light and creamy, see how it starts and how it ends: 

Then with the mixer on low, add the eggs one by one and turn the mixer to medium speed and beat it until light and creamy: 

Over the batter, sift in the cake flour and pour in the poppy seeds (you can also start mixing in the flour then pour in the poppy liquid as it’s running). 

Once you have a smooth batter and no flour bits unmixed, stop. 

Divide the batter between the two prepped pans and smooth it out. 

Bake until a cake tester comes out clean. If your cakes have domed a bit, slice off the top with a bread knife or a cake slicer (this makes it easier to stack them). 

How to make poppy vanilla swiss meringue buttercream 

Start by partially filling a pot with water (one that will fit a glass or metal bowl over it without the bowl touching the water) and bring the water to a simmer. 

Whisk together the egg white sand sugar then set the bowl over the simmering water. 

As you ‘cook’ it stir it often. The mixture will warm and the sugar granules will dissolve. Once you can’t detect any sugar granules it’s done. 

Transfer it to the bowl of a stand mixer (the bowl should be VERY clean and dry) and add the cream of tartar/lemon juice and begin whipping it. 

Whip until you can turn the whisk upside down and the meringue holds shape without drooping (a teeny bit of droop is ok).

Add the vanilla and salt, and some lemon extract if you like.

Then start adding the very soft butter, bit by bit. At first the buttercream will look like it’s broken, and once all the butter is in it might even turn to a soupy broken texture 

But keep whipping until it looks thick and kind of ‘bubbly’

When you can swipe it and it shows a smooth texture, it’s done whipping 

Stir in the poppy seeds and then transfer to a piping bag to frost the cake. 

Cake Filling Options 

In the photos I used my best lemon curd – you’ll only need a bit of it so you can halve or even quarter the recipe. You can also use my mason jar lemon curd (it’s quicker, makes less) or my meyer lemon curd. Alternatively use store-bought curd (taste it first to see if you like it!) or just more buttercream. 

How to make poppyseed cake ahead of time 

If you’re using the lemon curd as a filling, it can be made up to a week ahead of time. Store it in a sealed jar in the fridge. 

The buttercream can be made a few days ahead of time too, keep it in an airtight container in the fridge. Before using it to frost the cake bring it to room temperature and whip it to make it smooth. 

If making the cakes ahead of time, after they cool to room temperature wrap them in cling wrap tightly and freeze. They’ll keep in the freezer for 2-3 weeks. 

Once the cake is assembled, serve it the day of. Leftovers should be stored in the fridge.

Poppy Seed Cake Recipe

Poppy Seed Cake

Super soft poppy seed cake layers with a poppy seed vanilla swiss meringue buttercream

Prep Time: 30 minutes mins

Cook Time: 40 minutes mins

Yields: 2 eight inch layer cakes

5 from 5 votes

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Ingredients

• 240g or 1 cup buttermilk low or full fat
• 95g or or scant ¾ cups poppy seeds
• 3 lemons to zest
• 300g or 1 ½ cups granulated sugar
• ½ teaspoon fine sea salt
• 1 teaspoon pure vanilla extract or vanilla bean paste
• 113g or ½ cup butter unsalted and softened
• 66g or ⅓ cup flavorless oil
• 3 large eggs at room temperature
• 260g or 2 cups cake flour
• 2 ½ teaspoons baking powder
• Lemon curd optional, for filling

Vanilla Swiss Meringue Buttercream

• 4 large egg whites
• 224g or 1 cup plus 2 tablespoons cups fine granulated sugar
• ¼ tsp cream of tartar or half a teaspoon lemon juice
• ½ tsp fine sea salt
• 1 tsp vanilla extract
• 1 tsp lemon extract optional
• 336g or 3 sticks unsalted butter softened
• 3 tablespoons poppy seeds

Method

• The lemon curd can be made up to a week before cake assembly. Store it in the fridge in an airtight container. You won't need the full curd recipe for the cake, just about 1/4 cup of it so you can halve the recipe and have a bit of leftovers for other uses.

To make the cake

• Butter and flour two eight inch round metal cake pans. Preheat the oven to 325 F.
• Set the buttermilk in a small pot and stir in the poppy seeds. Set the pot over low heat. Once the mixture is warm, remove from heat and set aside.
• In the bowl of a stand mixer add the sugar and over it zest the lemons. Rub the zest into the sugar with your fingers to allow the oils to release. Stop once it resembles wet sand.
• Add the butter, oil, vanilla and salt to the bowl and affix the paddle attachment. Cream the mixture together until light and airy, about 3-5 minutes at medium speed. Stop the mixer and scrape down the bowl to ensure no bits remain unmixed.
• With the mixer on, add the eggs one by one. Once they are all in, turn the speed to medium and beat until you have a creamy mixture.
• Sift in the flour and baking powder and with the mixer on, pour in the buttermilk poppy seed mix. Mix to just combine.
• Divide the batter evenly between the two pans and smooth the batter so it’s in one layer.
• Bake the cakes until a cake tester comes out clean, the tops spring back - about 30-35 minutes. Let cool briefly in the pan then invert onto a cooling rack to completely cool.

To make the buttercream

• Make sure the butter is at a soft room temperature before you begin.
• Find a pot that will hold a glass bowl over it. Fill the pot a third of the way with water and set it over medium low heat and bring it to a simmer.
• In the glass bowl (off the heat) add the sugar and whisk in the egg whites. Once combined, set the bowl over the simmering water. Stir frequently with a rubber spatula to scrape up all the sugar on the sides as it warms. Once you can pinch the mixture and there are no sugar granules, it can be taken off the heat.
• Set the mixture in the bowl of a dry and clean stand mixer. Affix the whisk attachment and begin whisking on low, add the cream of tartar as it whips.
• Whip to stiff peaks, this can take up to 10 minutes but you’re looking for a meringue that holds shape (take the whisk out and turn it up - if the meringue droops it needs more time whipping).
• Add the vanilla and salt (and lemon extract if using) and then, with the mixer on, slowly add the butter - one tablespoon at a time. You don’t need to wait for each tb of butter to be mixed in but add it slowly. Once all the butter is in the buttercream might look soupy and broken, keep whipping until it thickens. When you can swipe it with a finger or an offset spatula and find it smooth, it’s done. Stir in the poppy seeds.

Assemble the cake

• If the cakes have domed, slice of the tops so you have even layers.
• Set one cake, facing up on a cake turntable. Pipe a buttercream border around the cake. In the center, spread the lemon curd (or spread more buttercream if that’s what you’re using).
• Set the second cake face down on top of the cake and pipe buttercream along the sides, turning the cake as you do. Smooth the buttercream in an even layer, using a bench scraper held against the sides as you turn the cake. Spread buttercream in an even layer, with some swoops, over the top of the cake.

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