Name: Blueberry Lemon Crumb Cake with Lemon Glaze
Prep time: 20 min
Cook time: 35 min
Total time: 55 min
Ingredients: ½ cup flour (70g); ½ cup brown sugar (110g); ½ tsp salt; 4 tbsp butter, softened; ¾ cup whole milk (160g); ½ cup vegetable oil (90g); 2 large eggs (100g); 1 tsp vanilla extract; zest of 2 lemons; ½ cup granulated sugar (104g); 3 tsp baking powder; ½ tsp salt; 2 cups flour (280g); 1½ cups blueberries (210g); 1 tbsp lemon juice; 6 tbsp powdered sugar

Jump to Recipe

This moist Blueberry Lemon Crumb Cake with Lemon Glaze is made with fresh blueberries and lemon zest, topped with an easy crumb topping and a sweet lemon glaze.

Do you love lemon blueberry treats as much as I do? Try Lemon Blueberry Mascarpone Cake, Lemon Blueberry Olive Oil Cake, or Lemon Blueberry Cookies.

Blueberry Lemon Crumb Cake with Lemon Glaze drizzled on top, cut into squares on parchment paper.

This Lemon Blueberry Crumb Cake is the perfect treat if you want something easy to throw together and not overly sweet with bright, fresh flavors. The crumb topping is not too heavy, and the lemon glaze is simple with just two ingredients.

The glaze is an easy addition, but it can certainly be left off if you want to limit additional sugar or simplify steps.

🔍 Recipe Testing

I made 4 different variations of this Blueberry Lemon Crumb Cake to determine the best ingredients and process. Here are my notes.

Sour Cream: My first test used sour cream to add moisture and flavor, but it took away from the flavor of the lemon and blueberries, and did not pair well. Instead of sour cream, the final recipe calls for vegetable oil, whole milk, and eggs to add flavor and moisture.
Pan Size: I baked this in both a 9x9 and an 8x8 metal baking dish. Both versions were great, but I prefer the 9x9 for a shorter, rather than a taller cake that is still moist and fluffy.
Baking Powder: I've made this cake with 3 teaspoons of baking powder, and separately with 2 teaspoons of baking powder. Using 3 teaspoons resulted in a very airy cake. I prefer using 2 teaspoons for a cake that is still light, but is slightly denser. Using 3 teaspoons of baking powder is better for tall Blueberry Lemon Poppy Seed Muffins.

🛒 Ingredients

Below are the ingredients needed to make Blueberry Lemon Crumb Cake with Lemon Glaze.

Whole Milk: Whole milk is best, but 1 or 2% can be used in a pinch.
Vegetable Oil: Olive oil can be used as a substitute.
Eggs: Use large eggs, pasture-raised if possible.
Vanilla Extract: Use real vanilla extract. Costco and other wholesale stores sell them for a low price per unit volume.
Granulated Sugar: Only a ½ cup for a cake that’s not overly sweet.
Baking Powder: For leavening.
Salt: To balance flavor.
Lemon: The zest of the lemon adds bright lemon flavor without any of the sourness of the juice. Be sure to zest only the bright yellow outer part of the lemon. A small amount of the juice is used to make the glaze and is sweetened with powdered sugar.
Flour: Use all-purpose, unbleached flour.
Blueberries: The amount of blueberries and the size of the blueberries will impact the baking time because they will affect the total water content of the cake. If you have extra blueberries, make this Cinnamon Sugar Dutch Baby with blueberries.
Brown Sugar: For the crumb topping. Granulated sugar can be used as a substitute, but brown sugar adds a little more flavor.
Butter: For the crumb topping. I use salted butter, softened to room temperature.
Powdered Sugar (not shown): For the crumb topping. Combined with a small amount of lemon juice for the glaze.

See the recipe card for full information on ingredients and quantities.

📝 How to Make Blueberry Lemon Crumb Cake with Lemon Glaze

Below are the step-by-step instructions and photos for how to make Blueberry Lemon Crumb Cake with Lemon Glaze.

*Note: The recipe card with instructions, ingredient list, and quantities is included further below these step-by-step photos.

Prep: Preheat the oven to 350°F. Butter and line a 9x9 square metal baking dish with parchment paper.

Step 1. Crumb Topping: Add the flour, brown sugar, salt, and softened butter to a small bowl and combine. Use your hands to scrunch up the mixture so that you have some smaller crumbs and some larger crumbs.

Step 2. Wet Ingredients: Add the milk, vegetable oil, eggs, vanilla extract, and lemon zest to a large bowl and whisk to combine.

Step 3. Dry Ingredients: Add the baking powder and salt and combine. Add the flour and gently combine with a spoon or spatula. Do not overmix.

Step 4. Fresh Blueberries: Add the blueberries and gently combine until just incorporated.

Step 5. Assemble: Pour the Blueberry Lemon Crumb Cake Batter into the prepared baking dish. Spread it evenly across the dish.

Step 6. Crumb Topping: Top the cake with the crumb topping.

Step 7: Bake: Bake the cake at 350°F for 35 minutes or until it is golden brown on top with a domed center that has fully set. Allow it to cool.

Step 8. Lemon Glaze: Combine the lemon juice and powdered sugar in a small bowl. Drizzle it over the crumb cake. Cut the cake into squares and serve.

🍽️ To Store and Reheat

To Store: This crumb cake is best eaten the same day because it is made with fresh blueberries. However, it can be enjoyed up to 1-2 days. Store the cake in the baking dish it was made in, covered with aluminum foil. This gives the cake room to breathe, but prevents it from going stale. Alternatively, press plastic wrap along the sides of the cake, but not the top, to prevent the sides from drying out.
To Reheat: Lightly toast in the oven for just a few minutes or in a toaster oven when serving it the next day. Add butter to each slice if desired.