Einkorn Apple Crumble Coffee Cake

Breakfast, dessert, and snack—this cake is so scrumptious, you’re going to want to eat large pieces of it throughout the day. And why not? It has fiber and nutrients from unpeeled apples, walnuts, and einkorn whole grain flour. Ok, it also has plenty of sugar and butter, but let’s focus on the fiber, sourdough discard, and cup of yogurt in the batter. Enjoy the tender texture of this unique cake with its bursts of apple flavor and crispy nutty crumble. It’s the perfect accompaniment to a hot cup of tea or coffee.

Apples

The inspiration for this apple walnut crumble cake is a recipe by Chef John. I was intrigued that he didn’t peel the apples in the batter, promising that the peel would disappear into the cake—and it does! You’ll want to avoid thick-skinned varieties of apple, and regardless of apple choice, make sure to dice it into small pieces so it cooks through. Check out Apple Rankings if you want to investigate the properties of different apple varieties. I used honeycrisp and gala apples. Red delicious and granny smith are examples of apples that tend to have thick skin.

Flour

I picked einkorn whole grain flour for this cake because it is slightly sweet and nutty. Other whole grain flours would be delicious also, and a soft white wheat flour might allow you to see more clearly the line of crumble midway through the cake. Of course, you can also use white all purpose flour or various high extraction flours. If you use a thirsty, higher-protein whole wheat flour, you may need to add more water to the batter. The target batter consistency is just a bit thinner than buttercream frosting.

Yogurt

If you use a strained yogurt (aka Greek yogurt), add 2-3 tablespoons of water to the batter. For my first test bake, I used 2% fat Greek yogurt and for my second test bake, I used whole milk Bulgarian yogurt, which is extra sour, with 1 tablespoon water. You can learn more about Bulgarian yogurt in the The Great Yogurt Feud episode of The Sporkful podcast.

Sugar

I made this cake twice, once with 200 grams sugar and once with 160 grams sugar. I found the higher amount of sugar was great on day one but made the cake a bit too sweet on subsequent days.

Sourdough Discard

I included 60 grams sourdough discard (about 1/4 cup) in the batter to add flavor and acidity—possibly a bit more loft from the baking soda and baking powder reactions as well, though yogurt is the main source of acidity. If you don’t have any sourdough discard, you can skip it without any changes to the rest of the recipe. And if you want to use substantially more discard, you’ll want to reduce the flour in the recipe or expect texture (and flavor) changes.

Spices

In my second go-around with this cake, I added 1/2 teaspoon ground ginger to the crumble, which already has ground cinnamon in it. I liked the ginger addition and you can experiment on the spice front, trying different ratios or other spices, such as cardamom. Or skip the spices altogether for more focus on the apple, einkorn, and walnuts.

Pan

I used 9 x 13 inch enameled stoneware pan for this cake. Stoneware heats up a bit slower than metal, so if you use a metal pan, reduce the bake time from 35 minutes to 30 minutes. Do make sure to begin checking on the cake earlier regardless of the bakeware you use.

The photos above show how the fineness of the walnut chop and 1 tablespoon of einkorn flour impacts the appearance of the crumble. Make sure to check out the process pics in the Photo Gallery after the recipe too.

Einkorn Apple Crumble Coffee Cake

This apple walnut crumble cake has so much flavor and texture. The tender, almost pudding-like einkorn cake with soft apple pieces is plenty decadent, but it is also divided and topped with a walnut-sugar crumble that takes the experience to another level.

Total Time

1 hour, 35 minutes

Ingredients

Crumble

• 1 1/2 cups finely chopped toasted walnuts (140 grams)
• 3 Tbsp melted unsalted butter (43 grams)
• 1/3 cup brown sugar (67 grams)
• 1/3 cup white sugar (67 grams)
• 1 tsp ground cinnamon (2.6 grams)
• 1/2 tsp ground ginger (1.3 grams)
• 1/4 tsp salt (1.4 grams)
• optional 1 Tbsp einkorn whole grain flour (8 grams)

Dry Ingredients

Wet Ingredients

• 2 apples, cored and diced, no need to peel
• 3/4 – 1 cup sugar (150-200 grams)
• 1/2 cup softened unsalted butter (113 grams)
• 60 grams sourdough discard (1/4 cup)
• 2 eggs
• 1 cup plain yogurt (200 grams)
• 2 tsp vanilla extract (4.7 grams)
• 1-4 Tbsp water to thin the batter, depending on yogurt and flour types (15-60 grams)

Instructions

• Please check out the photo gallery in addition to reading these instructions.

Crumble

• Toast the walnuts and finely chop them. Melt the butter.
• In a bowl, combine all the crumble ingredients and mix thoroughly.

Batter

• Preheat the oven to 350°F and grease a 9 x 13 inch pan. Note the different bake times for stoneware/glass versus metal.
• Whisk together the dry ingredients in a bowl and set aside.
• Cut the apple from the core and dice it into small pieces. There’s no need to peel the apple unless you’re using a thick-skinned variety. Set aside.
• In the bowl of a stand mixer, cream the butter and sugar.
• Add the sourdough discard and eggs, one item at a time, running the mixer in between.
• Mix in the the yogurt, vanilla extract, and apple pieces.
• Finally add the dry ingredients, running the mixer on low just until combined.
• Add water until the batter is just a smidge thinner than a butter cream frosting (with small apple chunks).

Assembly and Baking

• Spread half the batter into a layer on the bottom of the pan.
• Sprinkle on 1/3-to-1/2 the crumble, depending on how thick you want your top layer of crumble.
• Dollop and spread the second half of the batter on top of the crumble.
• Cover with the rest of the crumble, and gently-slightly press the crumb into the batter.
• Bake for 35 minutes or until a toothpick poked into the center of the cake comes out clean. For metal pans, a bake time of 30 minutes should be sufficient, but begin checking on the cake around 25 minutes.
• Let the cake cool as long as you can resist it and serve.

Photo Gallery