This isn’t anything like the cake you made from a box before you had to stop eating gluten. Instead, it is its own thing: lightly sweet, a little dense so the fork has something to do, tender and full of spices that play nicely with the nutty flavor of buckwheat.
Remember, you want light buckwheat, NOT the dark buckwheat you commonly see in grocery stores. You can make your own buckwheat flour by grinding buckwheat groats. Or, you could do what we commonly do: buy yourself a 3 pound bag of Bouchard Family Farms’ light buckwheat flour and keep it in the house for baking. We always have it in our pantry.
Prepare to bake. Heat the oven to 350°. Grease 2 8-inch cake pans with a neutral oil of your choice.
Beat the egg whites. Put the egg whites in the bowl of a stand mixer. Turn the mixer on high and beat the eggs to stiff peaks, about 7 minutes. If they are taking too much time to come to stiff peaks, add a pinch of cream of tartar to them. Use a rubber spatula to gently move the egg whites to a small bowl. Wipe out the bowl of the stand mixer.
Combine the dry ingredients. Whisk together the light buckwheat flour, the all-purpose flour, the baking powder, salt, cinnamon, ginger, and cloves in a large bowl. Set aside.
Cream the honey and eggs. Add the honey and egg yolks to the bowl of the stand mixer. MIx them on medium heat until they have become a creamy coherent liquid. Slowly, with the mixer running on low, drizzle in the coconut oil, along the side of the bowl, very slowly. Continue mixing until everything is well combined.
Finish the batter. With the mixer running on low, add ⅓ of the dry ingredients. Turn off the mixer to scrape down the sides of the bowl to move all the flour into the batter. Turn on the batter and pour in ½ of the cashew milk. Alternate dry ingredients and cashew milk until both are gone.
Gently, fold the egg whites into the batter. Swirl the egg whites in slowly until they are fully incorporated into the batter.
Bake the cake. Pour the batter into the prepared pans. Bake until the edges of the cake are starting to pull away from the edges of the pan, the top has a definite spring, and a toothpick inserted into the center comes out clean, about 20 minutes.
Take the cakes out of the oven. Prick holes in the top of the cake and drizzle a little honey over the top. Cool in the pan for 15 minutes, then remove from the pans. Cool completely.