Chestnut Crumb Coffee Cake
For brunch, the girls and I made a crumb coffee cake flavored with chestnut purée, and a streusel topping made with cinnamon and brown sugar for a rich, caramel flavor. Buttermilk gives a moist texture to the coffee cake; the result was just divine. Chestnut may not be a common flavor for coffee cake, but I guarantee that after tasting it, you'll be hooked.
I served the coffee cake with a big pot of masala chai. We all enjoyed ourselves. Hope your weekend is as relaxing and peaceful as ours!
Yields: 10 servings2-½ tablespoons brown sugar
7 tablespoons walnut powder (see tips)
½ teaspoon cinnamon extract (or ground cinnamon)
½ teaspoon ground ginger
2/3 cup granulated sugar
1 teaspoon rum extract
1-½ cups all-purpose flour
¼ cup potato flour
¼ teaspoon salt
1-¼ teaspoons baking powder
¼ teaspoon baking soda
8-½ tablespoons unsalted butter
¼ cup canola oil (or any neutral oil)
3/4 cup buttermilk
1 Meyer lemon, freshly zested
10 ounces chestnut spread, (3 small 100-gram tins)
Preheat the oven to 375°F.
For the walnut streusel crumb topping:
Using a pastry blender or the back of fork, combine the brown sugar, 3 tablespoons of all-purpose flour, ground ginger, 1/8 teaspoon of salt, 2-½ tablespoons of cold diced butter and walnut powder until it forms coarse crumbs of butter, walnuts and flour. Add the ¼ teaspoon of cinnamon extract. Do NOT over-mix. Set aside.
Making coffee cake:
Separate the egg yolks from the whites.
Beat the egg yolks in a mixing bowl with 1/3 cup of granulated sugar until they're pale, yellow; the texture of the egg yolks will be thicker. Add the rum extract.
In a separate bowl, sift the flours, baking powder and baking soda.
Combine the egg yolk mixture, zest of a lemon and the dry ingredients. Add the buttermilk, the rest of the melted butter and canola oil gradually until the cake batter is formed. I actually alternated the liquid ingredients and the dry ingredients.
In another bowl, add the remaining 1/8 teaspoon of salt to the egg whites and whisk for about 2 minutes at a low speed. Add the rest of the granulated sugar, increase the speed of your mixer and keep beating for another 2-3 minutes until it forms stiff peaks. Don't over-beat or the texture will become grainy.
Using a silicone spatula, mix 1/3 of the whipped egg whites into the egg yolk mixture to soften it. Add the rest of the whipped egg whites and fold in gently to get an airy batter.
Grease and slightly flour a non-stick (8-inch) square cake pan. Pour in 1/3 of the cake batter. Spread a layer of chestnut spread and cover with the rest of the cake batter. Top with the streusel crumb topping.
Bake for 5 minutes at 375°F; lower the temperature to 350°F and bake for another 35-40 minutes. A skewer or a toothpick inserted into a coffee cake should come out clean. Remove from the oven. and allow to cool completely.
If calories aren't a problem for you, you could substitute sour cream or whole milk yogurt for the buttermilk. I used buttermilk for a slightly tangy flavor.
Sifting the dry ingredients helps to get rid of lumps of flour and also to aerate the mixture when liquid is added. It's very important for all of your baking so you get a moist result.
You can either buy ready-made walnut powder (really just finely ground walnuts), or make it yourself. Grind the roasted* walnuts with a food processor or spice grinder. Make sure you stop before it turns into nut butter. I use the VitaMix Dry Blade Container. The result should be a fine mill.
Little reminder on how to roast nuts*: To release all the flavor and oil of the nuts, I like to roast them in the oven before using them. Spread the nuts onto a baking sheet. Place the tray in a preheated oven at 170°F. Roast the walnuts for about 15 minutes. Let the nuts cool completely. Do not roast the nuts over a temperature of 170°F or you'll risk breaking healthy fats and lose all the nutrients of the nuts. The only nuts I dry roast on the stove are pine nuts. They are smaller, cook more quickly and are much easier to watch and manipulate on the stove top.
For an adult version, you can add real rum in the chestnut spread and coffee cake batter.
Published By: on March 7, 2010.