Crumb-Topped Blueberry Cake

This blueberry cake is really a coffee cake in disguise. A tender, lemony batter goes into a 13×9 pan, gets covered with a layer of fresh blueberries, then blanketed in a thick cinnamon-walnut crumb topping that bakes into a crunchy, buttery streusel.

The lemon juice in the batter is what keeps this from tasting one-dimensional. It brightens the blueberries and cuts through the sweetness of the crumb topping, giving every bite a subtle tartness that makes you reach for another piece.

The crumb topping is generous and meant to be. Sugar, flour, cinnamon, soft butter, and chopped walnuts get worked together until crumbly, then scattered thick over the blueberries. During baking, the topping crisps and the berries beneath burst and bubble into a jammy layer between the soft cake and crunchy streusel.

Serve this warm. The contrast between the hot, juicy blueberries, soft cake, and still-crispy topping is at its best straight from the oven.

Kitchen Tips

• Don’t stir the wet ingredients into the dry too vigorously. Mix until just combined for a tender crumb. Overmixing develops gluten and makes the cake tough.
• Scatter the blueberries evenly across the batter. Clumped berries create soggy spots and uneven baking.
• The crumb topping should look shaggy and uneven, not packed smooth. Those irregular pieces create the best texture variation after baking.
• Fresh blueberries work best. Frozen berries release too much liquid and can make the center soggy. If using frozen, don’t thaw them first.

Variations

• Mixed berry: Use a combination of blueberries, raspberries, and blackberries for a mixed berry version.
• Pecan swap: Replace walnuts with chopped pecans in the crumb topping for a slightly sweeter, buttery nut flavor.
• Lemon glaze: Drizzle a thin lemon icing (powdered sugar and lemon juice) over the cooled cake for extra citrus punch.