Ingredients
Crumb Topping
- ½ cup (100 grams) dark brown sugar
- ¼ cup (50 grams) granulated sugar
- 8 tablespoons (113 grams) salted butter, melted and cooled (add ¼ teaspoon kosher salt if using unsalted butter)
- 1 teaspoon ground cinnamon
- 1 teaspoon ground cardamom
- 1 ¼ cups (156 grams) all-purpose flour
Cake
- ½ cup (100 grams) granulated sugar
- Zest of 2 medium lemons (zest only)
- 8 tablespoons (113 grams) unsalted butter, room temperature
- 1 large egg, room temperature
- ¼ cup (65 grams) whole milk, room temperature
- ⅓ cup (70 grams) full-fat sour cream, room temperature
- 1 teaspoon vanilla bean paste
- 1 ½ cups (180 grams) all-purpose flour
- 1 teaspoon ground cardamom
- ½ teaspoon baking soda
- ½ teaspoon baking powder
- ½ teaspoon kosher salt
Instructions
- Prepare Crumb Topping: Preheat the oven to 325°F (163°C). Line an 8×8 metal baking pan with parchment paper to prevent sticking. In a medium bowl, combine 1¼ cups flour, dark brown sugar, granulated sugar, ground cardamom, and cinnamon. Stir in the melted butter thoroughly, then mix until the topping becomes crumbly with large pieces. Set this aside for topping the cake later.
- Rub Lemon Sugar: In a separate small bowl, rub together the granulated sugar and lemon zest with your fingers until the zest is evenly distributed and fragrant, infusing the sugar with citrus oils.
- Cream Butter and Sugar: Using a handheld mixer or stand mixer fitted with a paddle attachment, beat the room temperature unsalted butter and lemon sugar mixture on medium speed until light and fluffy, about 3 minutes. This step aerates the butter for a tender crumb.
- Add Egg: Add the large egg to the butter mixture and beat until fully incorporated, ensuring the batter is smooth.
- Add Liquids: Mix in the whole milk, vanilla bean paste, and sour cream until just combined. Scrape down the sides of the bowl as needed to fully incorporate all ingredients, mixing for about 30 seconds.
- Mix Dry Ingredients: In a separate bowl, whisk together the 1½ cups all-purpose flour, salt, cardamom, baking soda, and baking powder, ensuring the leavening agents are evenly distributed.
- Combine Wet and Dry: Add the dry ingredients to the wet in two batches, mixing gently after each addition just until combined. Avoid overmixing to keep the batter thick and tender.
- Assemble Cake: Pour the thick batter into the prepared baking pan, spreading it out evenly with a spatula. Evenly sprinkle the crumb topping over the batter, covering the surface.
- Bake: Place the pan on the center rack of the oven to ensure even heat distribution, avoiding the top or bottom to prevent burning. Bake for 35-40 minutes or until a toothpick inserted into the center comes out clean. If the cake browns too quickly before 40 minutes, loosely cover with aluminum foil to prevent overbrowning.
- Cool and Serve: Allow the cake to cool slightly before slicing. This cake is best enjoyed the day it is made, but leftover slices can be softened by microwaving for 10-15 seconds to refresh the crumb topping’s texture.
Notes
- Use the fluff and spoon method if not weighing the flour: spoon flour lightly into the measuring cup and level off for accurate measurement.
- If you do not have salted butter for the crumb topping, add ¼ teaspoon of kosher salt to compensate.
- Room temperature ingredients help create a smooth batter and even baking.
- Do not overmix the batter to keep the cake tender and avoid toughness.
- Storing leftovers covered at room temperature is best; reheat gently to refresh texture.
- Prep Time: 15 minutes
- Cook Time: 35-40 minutes
- Category: Dessert
- Method: Baking
- Cuisine: American
