55min · 10 servings https://www.delish.com/cooking/recipes/a52625/lemon-blueberry-cake-recipe/ INGREDIENTS • 1 (15.25oz). box vanilla cake, plus ingredients called for on box • Juice and zest of 1 1/2 lemons, divided, plus more zest for garnish • 1 3/4 c. fresh blueberries, divided • 3 tbsp. all-purpose flour • 1 c. (2 sticks) butter, softened • 3 c. powdered sugar • 1/4 c. heavy cream • 1 tsp. pure vanilla extract • Pinch of kosher salt • 2 Thin lemon slices, for topping DIRECTIONS • Preheat oven to 350º and grease three 9" cake pans with cooking spray. Line with parchment. Prepare cake mix according to package directions, then stir in juice and zest of 1 lemon. • In a small bowl, toss 1 cup blueberries and flour until completely coated (to keep the berries from sinking)