Kumquat Fennel Seed Cake with Honey Mascarpone Icing and Almond Fennel Seed Brittle

This cake was inspired by Twitter. I host a monthly twitter chat on spices, #SpiceChat, and it came up that the chat planned for fennel seeds was one of the participant's birthdays. I chimed in that I would make him a fennel birthday cake for the next SpiceChat. After much pondering and a few experiments I came up with this cake that just so happened to be my birthday cake as well. It's a wonderful contrast of sweet and tart, creamy and crunchy, rustic and fancy. I hope you will make it for someone's birthday.

• Read Carol's blog post about this recipe

Makes a 9-inch round 4-layer cake

For the almond fennel seed brittle

1 ½ cups sugar
¼ cup fennel seeds
1 cup almonds, toasted, chopped

Line a large sheet pan with a silpat mat or parchment paper and set aside.

Place a medium-sized heavy-bottomed sauce pan over a medium-low heat and sprinkle in a few tablespoons of the sugar.  As the sugar begins to melt continue to add more sugar, a few tablespoons at a time, stirring with each addition. It's best to use a wooden spoon or silicone spatula for stirring because the extreme heat of the caramel won't travel up the spoon handle and burn your hand. Once the sugar is mostly melted, stop stirring and let it continue to cook undisturbed. Wash down the side-walls of the pan with water and a very clean pastry brush to melt away any errant sugar crystals. When the sugar reaches a deep golden caramel, turn off the heat and add the fennel seeds and chopped almonds. Stir to combine and immediately pour the brittle out onto the prepared sheet pan. Working quickly, spread the brittle out as thinly as possible. Resist the urge to touch it with your fingers, it's scalding hot! A silicone spatula works well for spreading. Let the brittle cool and then break it into pieces. The thinner it is, the easier it is to break up. I found breaking it by hand the best way to go. The brittle can be made a few days ahead, but must be stored in a dry environment in an airtight container.

For the kumquat marmalade

You can make your own kumquat marmalade (my recipe will be posted in a few days after one more test batch is made to ensure the recipe works.) or use any prepared marmalade you like.

2 cups marmalade, kumquat, orange or any other variety can be substituted
2 teaspoons fennel seeds, crushed

Mix the marmalade and fennel seed together and set aside until the cake is assembled.

For the cake

2 cups granulated sugar
zest of 1 orange
2 cups all-purpose flour
1 cup cornmeal
2 teaspoons fennel seed, ground
1 teaspoon baking powder
½ teaspoon sea salt
¼  teaspoon baking soda
1 cup plain yogurt, low-fat or full-fat
6 eggs
¼ teaspoon almond extract
1 cup olive oil

Preheat oven to 350°F with the oven rack positioned in the lower third of the oven.

Line two 9-inch cake pans with parchment paper.

In a small bowl combine the sugar and orange zest and rub together with your fingers to incorporate and release the oils from the zest. Set aside.

In a medium-sized mixing bowl, combine the flour, cornmeal, fennel seed, baking powder, baking soda, and salt. Using a whisk, stir well to thoroughly combine the ingredients. Set aside.

In another medium-sized mixing bowl, combine the sugar, yogurt, oil, and almond extract. Whisk together to fully combine. Add the liquid ingredients to the dry ingredients, stirring only enough to combine the two. Over mixing will make the cake tough.

Divide the batter evenly between the two prepared cake pans and bake for 23-25 minutes. The cakes should be slightly golden brown around the edges, slightly domed in the center and spring back when touched lightly. Let cool for 10 minutes on a cooling rack and then turn the cakes out of the pans to continue to cool completely on the cooling rack.

For the Honey Mascarpone Icing

½ cup granulated sugar
zest of 1 orange
16 ounces mascarpone
1 ½ cups whipping cream
¼ cup honey

In a small bowl combine the sugar and orange zest and rub together with your fingers to incorporate and release the oils from the zest. Set aside.

Place the mascarpone in the bowl of a stand mixer fitted with a whisk attachment, and beat on a medium speed until smooth, 2-3 minutes. Add the whipping cream and continue to beat on a medium speed until it begins to thicken, about 2 minutes. Slowly add the sugar as the cream continues to beat and then add the honey.  Scrape down the sides of the bowl as needed. Continue mixing until all the ingredients are incorporated and the icing is thick and creamy. Cover and keep in the refrigerator until ready to assemble the cake. Can be made a day ahead.

To assemble the cake

With a long serrated knife, slice each cake layer horizontally to create four layers of cake. Place one layer of cake on a cake plate and spread 3/4 cup of marmalade over it. Add a second layer of cake and spread about 1 ½ cups of icing over it. Top with a third layer of cake and cover this one with another ¾ cup of marmalade. Place the final layer of cake on top and cover the top and sides with icing.

If you like to pipe, add a decorative piped boarder around the top edge of the cake, but this is not necessary.

Add a tablespoon of water to the remaining ½ cup of marmalade and warm it in the microwave just until it's runny. Strain the marmalade through a fine mesh strainer reserving both the marmalade broth and peel. Once the clear marmalade has cooled, pour it in the center of on the top of the cake and using a small off-set spatula gently spread it out toward the edge of the cake, without letting it drip over the edge.

Press the pieces of fennel seed almond brittle onto the sides of the cake and add the reserved marmalade peel around the top edge as a decorative garnish if desired.

Cover with a cake dome if you have one and store the cake in the refrigerator. Remove a few hours before serving so it can warm up. The cake holds well in the refrigerator and can be made a day ahead, but it would be best to add the brittle the day it is going to be served so it doesn't become sticky and melted.