Knotweed Mousse Cake With Maple Buttercream and Wildflowers

When I was planning my spring hunt with Chris Bohnhoff last year, we made a dinner to be part of the video. As luck would have it though, the day was rainy and the lighting inside wasn’t up to scratch, so our dinner didn’t make the footage.

We had a risotto of fresh morels, spruce cured salmon with a fiddlehead salad and lamb loins marinated in wild peppermint. The dinner was just fine, but what I put the most work into was the dessert. I wanted to make something that represented the farm that’s taught me so much about the wild foods where I live.

I dreamed up  a wild rice sponge rolled around a mousse of knotweed from the garden, frosted with a buttercream sweetened with the farm’s maple syrup and garnished with wildflowers and herbs from the prairie on top of the nearby bluff. It took four or five tries for me to be happy with it, but in the end it was worth it. It’s a dessert, and an expression of what I’ve come to love about the farm.

The cake itself is really not too difficult, the wild rice sponge and mousse are just two easy recipes combined and the frosting/garnishing are optional, but pretty. Here’s how I made it.

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To show a little of the possibilities. I worked on a simpler version with rhubarb sauce, since it and the knotweed are distant cousins and taste eerily similar.

An unfrosted cake with strawberry-rhubarb sauce and blueberries.

I’ve listed the 3 sub-recipes for the cake below. To assemble it or something like it, you’ll want to make the cake first, then stuff with the mousse, roll and chill to set. Before serving, frost it with the butter cream, then decorate with the flowers (if using) just before serving.

Special thanks to Chris Bohnhoff for shots of the assembly and the frosted cake.

Print Recipe

4.5 from 2 votes

Wild Rice Sponge Cake

A rolled cake made of wild rice flour with knotweed filling

Prep Time1 hr

Cook Time45 mins

Course: Dessert, Snack

Cuisine: French

Keyword: Knotweed, Wild Rice Flour

Servings: 8

Equipment

• Stand mixer or beaters

Ingredients

• 4 large eggs
• 1/2 cup white sugar
• 3/4 cup wild rice flour
• 2 ounces 1/2 stick unsalted butter
• Pinch of salt
• 1 teaspoon of equal parts toasted and ground: cinnamon nutmeg, allspice, and cloves (optional)
• 1/2 teaspoon powdered ginger
• Pinch of salt

Instructions

• Preheat an oven to 350. Melt the butter. In a stand mixer or bowl, beat the eggs with the sugar until light, fluffy, and doubled in volume, fold in the spices, salt, and wild rice flour, along with the melted butter. Line a cookie sheet with parchment and oil it to prevent sticking. Pour in the batter and spread until smooth. Bake the sponge for 12 minutes, then allow to cool for a minute or two. lay a towel on a flat surface, then, very carefully lay the sponge cake on top, removing the parchment. Roll the sponge cake up in the towel to help it form the jelly roll shape it will become. If it tears a bit, don't worry, you can cover it up with butter cream later, or just slice as-is, it won't be too noticeable.

Notes

Instead of knotweed, you could easily make this with a puree of cooked berries or jam. A buttercream flavored with orange, mint, vanilla, or a combination would be great too. You can definitely substitute all purpose flour or a combination of nut flours for the wild rice flour too, which yields a more resilient cake.

Print Recipe

4.5 from 2 votes

Knotweed Mousse

Makes enough mousse to fill the wild rice cake, or serve 4-6 on it's own with fruit

Prep Time30 mins

Cook Time5 hrs

Course: Dessert, Snack

Cuisine: American

Keyword: Chocolate Mousse, Knotweed

Ingredients

• 2 cups sweetened knotweed puree see my recipe here
• 4 leaves gelatin 1.25 tablespoons powdered gelatin can be substituted
• 3 egg whites whipped until stiff with 1/8 cup white sugar
• 2 tablespoons roughly chopped wild peppermint optional

Instructions

• Bloom the gelatin in ice water until soft, then gently heat the knotweed puree and whisk in the gelatin until dissolved. Chill the mixture, whisk to relax the gelatin, then fold in the beaten egg whites and wild mint. Chill again, covered with plastic wrap until ready to use/serve.

Notes

Sweetened knotweed puree (see my recipe here)