Easy One-Bowl Coffee Cake

Ingredients

• For the topping:
• 4 ounces light brown sugar
• 2 1/2 ounces whole wheat flour
• 1 tablespoon ground cinnamon
• 1/4 teaspoon Diamond Crystal kosher salt; for table salt, use half as much by volume or use the same weight
• Shy 1/4 teaspoon ground cardamom
• 2 ounces unsalted butter, soft, about 70°F
• For the coffee cake:
• 14 ounces plain or quick-toasted sugar
• 6 ounces unsalted butter, about 65°F
• 4 teaspoons baking powder
• 1 teaspoon Diamond Crystal kosher salt; for table salt, use half as much by volume or use the same weight
• 1/2 ounce vanilla extract
• 3 large eggs, brought to about 65°F
• 12 ounces all-purpose flour, such as Gold Medal
• 14 ounces plain Greek yogurt, any percentage will do, brought to about 65°F

Directions

1. For the topping, place the brown sugar, whole wheat flour, cinnamon, salt, cardamom, and butter in the bowl of a stand mixer with the paddle attached. Run the mixer on low until the mixture looks sandy and evenly blended. Tip it out onto a large plate or a sheet of parchment. If you want to hold it for later, pack the topping into an airtight container and refrigerate it for up to 1 week, or freeze it for 6 months. Swipe the bowl and paddle clean with a paper towel, then move right on to the cake batter without washing them.
2. For the coffee cake, set an oven rack in the lower-middle position and heat the oven to 350 degrees F (180 degrees C). Add the sugar, butter, baking powder, salt, and vanilla to the stand mixer bowl with the paddle attached. Mix on low just until everything is dampened, then turn the mixer to medium and beat until the mixture is pale, fluffy, and soft, about 10 minutes. Stop and clean down the bowl and beater with a flexible spatula, then start the mixer again on medium. Beat in the eggs 1 at a time, waiting until each one disappears into the batter before adding another.
3. Scrape the bowl and beater again with a flexible spatula, then return the mixer to low. Add about 1/3 of the flour, followed by 1/3 of the Greek yogurt. Continue with the remaining flour and yogurt in thirds the same way. Use a flexible spatula to fold the batter 1 or 2 times, then transfer it to a parchment-lined 9- by 13- by 2-inch anodized-aluminum baking pan. Smooth the batter evenly in the pan, then scatter the prepared topping over it by the handful, pressing each handful in your palm so it forms little streusel clumps.
4. Bake the coffee cake until it rises and feels set, about 40 minutes; a toothpick poked into the center should come out with a few damp crumbs. Cool the cake in the pan for about 30 minutes before serving, since the crumb will be soft and gummy until it has time to settle. Slice it into squares with a butter knife, using the parchment to help you slip an angled spatula under the first piece. To keep it tasting fresh, cut only what you plan to serve. Press plastic wrap or wax paper against the cut side, cover the top of the pan with aluminum foil, and keep leftovers at room temperature for up to 3 days.