Martha Stewart Blueberry Crumb Cake

Martha Stewart blueberry crumb cake is a moist, buttery square cake with juicy blueberries and a thick brown sugar streusel that comes together in 70 minutes. It's an easy summer dessert for brunch, potluck tables or afternoon snacks, and it's simple enough to make in one 9-inch pan.

Squeeze the streusel into large, moist crumbs and chill it before it goes on the cake. Skip that and the butter melts into the batter, so you lose the crisp topping.

Martha adds a pinch of allspice to the batter, which gives the cake a gentle warmth that plain blueberry cakes don't have. Her thick, stiff batter also holds the berries in place, and a teaspoon of flour tossed with them keeps them from sinking.

Martha Stewart Blueberry Crumb Cake

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Course: DessertCuisine: AmericanDifficulty: Easy

Servings

9

servings

Prep time

20

minutes

Cooking time

50

minutes

Calories

380

kcal

A dense, tender crumb holds pockets of jammy blueberries under a crisp brown sugar streusel. Because the batter is stiff, the cake bakes up sturdy enough to cut into clean squares.

Ingredients

• 1 cup all-purpose flour
  

• 1/2 cup packed light-brown sugar
  

• 1/4 teaspoon salt
  

• 1/2 cup (1 stick) cold unsalted butter (cut into tablespoons)
  

• 4 tablespoons unsalted butter, softened, plus more for pan
  

• 1 1/2 cups all-purpose flour (spooned and leveled), plus more for pan and 1 teaspoon for blueberries
  

• 1 1/2 teaspoons baking powder
  

• 1/2 teaspoon baking soda
  

• 1/4 teaspoon salt
  

• 1/4 teaspoon allspice
  

• 3/4 cup sugar
  

• 1 large egg
  

• 2/3 cup buttermilk
  

• 1 1/2 cups blueberries
  

Directions

• Make the streusel: Preheat the oven to 350°F, then stir 1 cup flour, 1/2 cup brown sugar and 1/4 teaspoon salt together in a medium bowl. Cut in 1/2 cup cold butter with your hands or a pastry blender until large, moist crumbs form, then chill.
• Prep the pan: Butter and flour a 9-inch square baking pan. That keeps the cake from sticking when you cut it later.
• Mix the dry ingredients: Whisk 1 1/2 cups flour, 1 1/2 teaspoons baking powder, 1/2 teaspoon baking soda, 1/4 teaspoon salt and 1/4 teaspoon allspice in a medium bowl. Set it aside while you cream the butter.
• Cream the butter: Beat 4 tablespoons softened butter and 3/4 cup sugar with an electric mixer in a large bowl until fluffy. Then add the egg and beat well.
• Add flour and buttermilk: Add the flour mixture and 2/3 cup buttermilk to the bowl in alternating batches until just combined. The batter will be very stiff, so don't worry if it looks thick.
• Fold in the berries: Toss 1 1/2 cups blueberries with the remaining 1 teaspoon flour in a bowl, then fold them gently into the batter. Spoon the batter into the prepared pan and spread it level.
• Top and bake: Sprinkle the streusel evenly over the cake, then bake for 45 to 50 minutes. It's done when the top is golden brown and a tester comes out clean.
• Cool completely: Let the cake cool completely in the pan before you cut it. Then slice it into 9 squares.

Tools for this recipe

• USA Pan 8x8 square cake pan, KitchenAid 5-speed hand mixer, Spring Chef dough blender (pastry cutter). As an Amazon Associate I earn from qualifying purchases.

FAQs

Why do the blueberries sink in some crumb cakes?

Berries sink when the batter is thin and they're coated in moisture. Tossing them with 1 teaspoon of flour before folding them in helps them stay suspended, and this stiff batter holds them in place too.

How do I get a crisp streusel instead of a soggy one?

Squeeze the butter, flour and sugar into large, moist crumbs and chill them before topping the cake. Cold crumbs bake into a crisp layer instead of melting into the batter.

Can I use frozen blueberries?

Yes, but don't thaw them first. Toss them frozen with the flour and fold them in right before baking, since thawed berries bleed purple into the batter. You may need a few extra minutes in the oven.

How should I store leftover crumb cake?

Cover the pan tightly or move the squares to an airtight container, and keep them at room temperature for up to 2 days. In the fridge it keeps a bit longer, but the streusel softens, so I like to warm a square in a 300°F oven for a few minutes.

What can I use if I don't have buttermilk?

Stir 2 teaspoons of lemon juice or white vinegar into 2/3 cup of milk and let it sit for 5 minutes. It won't be quite as thick as real buttermilk, but it gives the same tang and tender crumb.