The old-fashioned sour cream coffee cake from Flour bakery is unbelievable. It's moist, a little dense, with a fantastic crumb. It's unbelievably good. I'd eat it all day long if I could. Flour bakery often uses crème fraîche, which is an acidic ingredient, much like sour cream. Sour cream has a fat content of about 14 %, while crème fraîche hovers around 40 % fat. That extra fat does wonders for cakes and baked good adding so much flavour, yielding a moist cake that is a little more dense, but dense in a good way!
Unfortunately, crème fraîche isn't very easy to find in grocery stores. Sometimes they have it and sometimes they don't. Sour cream is definitely more readily available and so for this cinnamon apple crumb cake, I used sour cream, which is a great baking substitution to keep in mind.
The best part of coffee cakes and crumb cakes is the deliciously crumbly streusel topping. Of course, the problem with coffee cake is also the deliciously crumby streusel topping. Streusel is a great topping for cakes and muffins, and it's often made with equal parts of flour, ground nuts, sugar, and butter, by weight.
This is quite different from a crumble topping like on this apple crumble cake where the crumble topping is more clumpy and made with oats, like it might be on an apple crisp. Streusel is made with melted butter and the crumble is made with softened, room temperature butter. The textures are quite different.
This coffee cake is light, moist and comforting. I made the streusel topping from a graham flour mixture I'd put together when making homemade graham crackers. Remember that graham flour is a nutty mixture of flours made from wheat germ and whole wheat flour, so it goes perfectly with the thin layer of sliced tart apples just below it. This has less apples than the apple yogurt cake, but that's to make room for the cinnamon streusel. Worth it!
If you'd prefer to eat your coffee cake in the form of a muffin, give these plum cardamom coffee cake muffins a try!
Cinnamon apple crumb cake
- 60 grams (½ cup) all-purpose flour
- 30 grams (¼ cup) whole wheat flour
- 10 grams (1 tablespoon) wheat germ
- 7.5 mL (1½ teaspoon) ground cinnamon
- 100 grams (½ cup) dark brown sugar
- 58 grams (¼ cup) unsalted butter melted
- 250 grams (2 cups) all-purpose flour
- 5 mL (1 teaspoon) baking powder
- 2.5 mL (½ teaspoon) baking soda
- 2.5 mL (½ teaspoon) Diamond Crystal fine kosher salt
- 115 grams (½ cups) unsalted butter room temperature
- 250 grams (1¼ cups) light brown sugar
- 7.5 mL (1½ teaspoon) pure vanilla extract
- 2 large eggs room temperature
- 250 mL (1 cup) sour cream (14% fat) or crème fraîche
- 1 apple such as Cortland, peeled, cored and sliced thin
- Prepare a 9x9 inch square brownie pan (or cake pan) by buttering and flouring it, lining the bottom with a square of parchment. Set aside
- Preheat the oven to 175 ºC (350 ºF).
- With a fork, stir together all the streusel ingredients in a small bowl. Continue mixing until the streusel clumps a little and all the dry ingredients are moistened. Set aside.
- In a medium bowl, whisk together the flour, baking soda and salt. Set aside for later.
- In the bowl of an electric mixer fitted with the paddle attachment, cream the butter and the light brown sugar. Add the vanilla, followed by the eggs, one at a time, scraping down the bowl as needed between each addition.
- With the mixer on low, add the dry ingredients alternately with the sour cream, beginning and ending with the dry ingredients. Give the cake batter a couple stirs with your spatula to be sure all the ingredients have been evenly incorporated and the batter is smooth.
Assembly and baking
- Spread the batter evenly in the prepared cake pan.
- Top with a layer of the thinly sliced apple. Press them down gently.
- Sprinkle the prepared streusel topping over the apples. Press the streusel down gently.
- Bake the coffee cake for 40–50 minutes, checking it with a cake tester to be sure it is done.
- Let the coffee cake cool completely in the pan on a wire rack before serving.