Ingredients
Crumb Topping
- 3/4 cup (95 grams) all purpose flour
- 1/2 cup (100 grams) granulated sugar
- 1/2 cup (100 grams) dark brown sugar
- 1 teaspoon ground cardamom
- 1 teaspoon cinnamon
- 8 tablespoons (113 grams) salted butter, melted and cooled (add 1/4 teaspoon kosher salt if unsalted butter used)
Cake Batter
- 1/2 cup (100 grams) granulated sugar
- Zest of 2 medium lemons (about 2 teaspoons)
- 8 tablespoons (113 grams) unsalted butter, room temperature
- 1 large egg, room temperature
- 1/4 cup (65 grams) whole milk, room temperature
- 1/3 cup (70 grams) full fat sour cream, room temperature
- 1 teaspoon vanilla bean paste
- 1 1/2 cups (180 grams) all purpose flour
- 1 teaspoon ground cardamom
- 1/2 teaspoon baking soda
- 1/2 teaspoon baking powder
- 1/2 teaspoon kosher salt
Instructions
- Prepare the Crumb Topping: In a medium bowl, combine 3/4 cup flour, dark brown sugar, granulated sugar, cardamom, and cinnamon. Stir in the melted and cooled butter until well mixed. Continue stirring in the remaining flour until the mixture is crumbly with some large pieces. Set aside.
- Preheat the Oven and Prepare Pan: Preheat your oven to 325°F (163°C). Line an 8×8 inch metal baking pan with parchment paper for easy removal.
- Make Lemon Sugar: Rub together the granulated sugar and lemon zest in a small bowl until the sugar is fragrant and well combined.
- Cream Butter and Lemon Sugar: Using a handheld or stand mixer, beat the room temperature unsalted butter and lemon sugar until the mixture is light and fluffy, about 3 minutes.
- Add Egg and Dairy: Mix in the egg until just combined. Then add the milk, vanilla bean paste, and sour cream, mixing for about 30 seconds until incorporated. Scrape down the sides of the bowl to ensure even mixing.
- Combine Dry Ingredients: In a separate bowl, whisk together the flour, cardamom, baking soda, baking powder, and kosher salt.
- Incorporate Dry Ingredients: Add the dry ingredients to the wet mixture in two batches, mixing until just combined. Do not overmix. The batter will be thick.
- Pour Batter into Pan: Spread the thick batter evenly in the prepared baking pan.
- Add Crumb Topping: Evenly sprinkle the prepared crumb topping over the batter, covering it completely.
- Bake the Cake: Place the pan on the center rack of the oven and bake for 35-40 minutes, or until a toothpick inserted into the center comes out clean. If the cake starts to brown too quickly, loosely cover with foil to prevent over-browning.
- Cool and Serve: Allow the cake to cool slightly before slicing. This cake is best eaten the day it’s made, but can be softly reheated in the microwave for 10-15 seconds per slice to revive the crumb texture.
Notes
- Use the fluff and spoon method to measure flour if not weighing: gently fluff the flour, spoon it into the measuring cup, and level off with a knife to avoid packing.
- If you only have unsalted butter for the crumb topping, add 1/4 teaspoon kosher salt to compensate for the missing salt.
- Room temperature ingredients help the batter come together smoothly and create a tender cake.
- To soften leftovers, microwave each slice for 10-15 seconds before serving for the best texture.
- Prep Time: 15 minutes
- Cook Time: 40 minutes
- Category: Dessert
- Method: Baking
- Cuisine: American
- Diet: Vegetarian