2⅓ cups (280 grams) gluten free flour blend, such as Bob’s Red Mill's 1-to-1
2 teaspoons baking soda
1 teaspoon baking powder
pinch freshly-grated nutmeg
½ teaspoon salt
1 tablespoon fresh tarragon, finely chopped, or 1 teaspoon dried
zest from 1 large lemon (reserve a pinch for the buttercream)
juice from ½ lemon
½ teaspoon lemon extract
1 teaspoon vanilla extract
for the buttercream
7 egg whites
1¼ cup (198 g) sugar, superfine if you have it
3 sticks (1½ cup) unsalted butter, cool but not cold and cut into cubes
2 tsp vanilla extract
pinch of lemon zest
pinch of salt
Instructions
for the cake
Preheat oven to 325 degrees Fahrenheit. Butter 3 x 6 inch cake pans (or 2 x 8 inch cake pans), line with rounds of parchment paper, dust with flour and tap out the excess.
Bring a pot of water to a boil, then boil the peas for about 3 minutes, until tender. Drain the peas and puree.
Beat the oil and sugar in a stand mixer fitted with a paddle attachment (or a handheld mixer) on medium speed for about 3 minutes, then reduce the speed and add the eggs one at a time. Beat on medium speed until combined and creamy, about 3 more minutes.
Sift the dry ingredients together and add slowly, mixing on low speed just until combined. Add the pea puree, tarragon, lemon juice, zest, lemon extract and vanilla extract and mix briefly until smooth.
Distribute the batter evenly in the prepared pans and bake for 20 minutes without opening the oven, then rotate the pans and bake for an additional 5-7 minutes or until a toothpick inserted in the center of the cake comes out clean. Place the pans on cooling racks for 15-20 minutes or until the pan is cool enough to handle.
Run a sharp knife around the edges of the pans to loosen the cakes, then turn the cakes out onto the cooling racks, remove the parchment paper, and allow to come to room temperature. To assemble, level cakes if desired. Place the first layer on a cake board or a serving plate smooth side down and spread a generous layer of buttercream on top. Place second layer face down, gently press, and ice the top with buttercream. Place final layer face down and ice the top and sides of the cake. If your kitchen is warm and at any point the cake feels unsteady, pop it in the fridge for 10 minutes or so to firm up the buttercream. Decorate with flowers and serve. Keeps well for 3-4 days, allow to come to room temperature before serving.
for the buttercream
Wipe the metal bowl of an electric stand mixer, whisk attachment and a whisk with vinegar or lemon juice and a paper towel to remove any trace of grease.
Prepare a double boiler by filling a saucepan with 1 inch of water and bringing to a boil, then reduce to a simmer. Place a metal mixing bowl over the pot of simmering water (bowl should fit snugly but should not touch the water) and add the egg whites and sugar. Stir constantly with a whisk until the temperature reaches 140 degrees on a candy thermometer or until all the sugar has dissolved, the egg whites are hot and the mixture is foamy. Remove from heat.
Beat egg whites and sugar on high speed until the bottom of the bowl is completely neutral, about 10 minutes. Switch to the paddle attachment and turn mixer on low speed.
Begin slowly adding the butter pieces and mix until the texture is smooth. If the buttercream curdles, keep mixing, it'll come back together.
Add the vanilla extract, and lemon zest and mix well. Taste, add a pinch of salt, and taste again. If you'd like a stronger lemon flavor, add ¼ tsp lemon extract, tasting after each addition until the desired flavor is achieved.
You can store buttercream in the fridge in an airtight container for 3 days, or in the freezer for up to 6 weeks.
Recipe by oh honey bakes at https://ohhoneybakes.com/sweet-pea-tarragon-cake-gluten-free/