Greek Yogurt Streusel Coffee Cake

1. Making the Topping

Begin by preparing the streusel topping. In a stand mixer fitted with a paddle attachment, combine 4 ounces of light brown sugar, 2.5 ounces of whole wheat flour, 1 tablespoon of ground cinnamon, 0.25 teaspoon of Diamond Crystal kosher salt, a shy 0.25 teaspoon of ground cardamom, and 2 ounces of soft unsalted butter. Mix on low speed until the mixture resembles sandy crumbs. This topping can be made ahead and stored in the refrigerator for up to a week or in the freezer for six months.

2. Preheat the Oven

Adjust your oven rack to the middle position and preheat the oven to 350°F (180°C).

3. Creaming the Base

In your stand mixer, combine 14 ounces of sugar, 6 ounces of unsalted butter, 4 teaspoons of baking powder, 1 teaspoon of Diamond Crystal kosher salt, and 0.5 ounce of vanilla extract. Start mixing on low speed to moisten the ingredients, then increase to medium speed and cream for about 10 minutes until the mixture is soft, fluffy, and pale. This step is crucial because it incorporates air into the batter, giving your cake a light and tender crumb.

4. Adding the Eggs

Add the eggs one at a time, ensuring each egg is fully incorporated before adding the next. Continue mixing until the mixture is smooth and emulsified.

5. Mixing Dry and Wet Ingredients

Alternate adding the 12 ounces of all-purpose flour and 14 ounces of Greek yogurt to the batter. Start by adding one-third of the flour, then one-third of the yogurt, and repeat until all ingredients are incorporated. Use a stand mixer on low speed and a flexible spatula to scrape down the sides as needed. This method ensures a smooth batter without overmixing, which can make the cake dense.

6. Preparing to Bake

Scrape the batter into a parchment-lined 9- by 13- by 2-inch anodized-aluminum baking pan and spread it into an even layer using a flexible spatula.

7. Adding the Topping

Sprinkle the prepared streusel topping evenly over the batter. Squeeze the topping in your palm to form small nuggets before sprinkling it over the batter for a crunchy texture.

8. Baking

Bake the coffee cake in the preheated oven at 350°F (180°C) for about 40 minutes. The cake is done when it is puffed and firm, and a toothpick inserted into the center comes out with moist crumbs.

9. Cooling

Allow the cake to cool in the pan for about 30 minutes. This cooling period is essential to let the crumb set, as the cake will be quite soft and gummy initially.

10. Serving and Storing

Cut the coffee cake with a butter knife, using an angled spatula to serve. Leftovers can be stored at room temperature for up to three days. Keep the cut surface covered with plastic wrap or wax paper and the top covered with foil to maintain freshness.