
The reviews are in: Costco shoppers are OBSESSED with their new bakery offering, the Lemon-Blueberry Loaf Cake, and here at Delish, we agree that it’s practically perfect… so perfect that we had to develop a copycat version of it! Our rendition starts with a tender lemon batter filled with fresh blueberries, so you get plenty of blueberries in every bite. Then it’s topped with the signature crunchy butter streusel topping and tangy lemon glaze that makes the Costco version so irresistible. Now you can enjoy this cake even if you aren’t a Costco member or if your location doesn’t carry it. Even if you do have the opportunity to buy it, give our version a try. It's actually a rewarding process to re-create the cake and ace baking it at home in your own kitchen.
Online reviewers of the cake have noted some inconsistencies when it comes to the amount of blueberries in the cake, and some state that the cake batter isn’t all that lemony, but you don’t have to worry with our recipe. Follow it and you’ll get the same results every time, with blueberries aplenty and lemon goodness in the batter and the glaze.
Tip: Bake this version in a 9"x5" loaf pan, which gives just the right amount of room for all the lemon-blueberry goodness without requiring a specialty pan.
Have you tried the Costco version yet? Let us know what you think of our recipe in the comments below!
Ingredients
Butter Streusel
- 1/4 cup
(40 g.) all-purpose flour
- 2 Tbsp.
granulated sugar
- 2 Tbsp.
packed light brown sugar
Large pinch of kosher salt
- 2 Tbsp.
unsalted butter, melted, slightly cooled
Cake
- 1/2 cup
safflower or canola oil, plus more for pan
- 1 3/4 cups
(210 g.) all-purpose flour
- 1 cup
(200 g.) granulated sugar
- 2 tsp.
baking powder
- 3/4 tsp.
kosher salt
- 3
large eggs
- 1 cup
plain Greek yogurt
- 1 Tbsp.
finely grated lemon zest (from about 1 lemon)
- 2 tsp.
pure vanilla extract
- 2 cups
fresh blueberries, divided
Lemon Icing
- 1/2 cup
(60 g.) confectioners' sugar
- 2 tsp.
(or more) fresh lemon juice
- 1/2 tsp.
light corn syrup
Directions
Butter Streusel
Preheat oven to 350°. In a small bowl, whisk flour, granulated sugar, brown sugar, and salt until combined. Pour butter over dry ingredients and stir until combined. Set aside until ready to use.
Cake
- Step 1Brush a 9"x5" loaf pan with oil. Line pan with parchment, leaving a 2" overhang on 2 opposite long sides. Brush parchment with oil.
- Step 2In a medium bowl, whisk flour, granulated sugar, baking powder, and salt until well combined.
- Step 3In a large bowl, whisk eggs, yogurt, lemon zest, vanilla, and oil until well combined. Pour dry ingredients into egg mixture and mix just until combined. Add 1 1/2 cups blueberries and fold just until distributed.
- Step 4Scrape batter into prepared pan; smooth top with a spatula. Scatter remaining 1/2 cup blueberries over, then gently press blueberries into batter. Using your hands, crumble butter streusel into clumps over batter.
- Step 5Bake cake, tenting with foil during the last 30 minutes if darkening too fast, until a tester inserted into the center comes out clean, 1 hour, 20 minutes to 1 hour, 30 minutes.
- Step 6Transfer pan to a wire rack and let cool 10 minutes. Using parchment overhang, carefully transfer cake to wire rack. Remove parchment and let cool.
Lemon Icing
- Step 1In a medium bowl, whisk confectioners’ sugar, lemon juice, and corn syrup, adding more lemon juice by the drop if needed, until smooth and thick yet pourable.
- Step 2Drizzle glaze over cooled cake. Let rest until glaze sets, about 30 minutes.