With the right box mix this could be made gluten free but I’ve only made it traditionally as I tend to make it 3 layers and the strength of gluten based flour really works when you’re doing that.

For personal reasons, this cake needs to be cut with a “Murder Knife”, the largest knife you have that you might use to murder an invading viking, an aggressive dragon, etc. I used a Kukri once and a brass knuckles style combat knife the first time.


  • 1 (15.25oz). box vanilla cake, plus ingredients called for on box; I used a Duncan Hines French Vanilla cake mix
  • 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


  1. 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.
  2. In a small bowl, toss 1 cup blueberries and flour until completely coated (to keep the berries from sinking). Gently fold blueberries into the batter. Please note that they are going to sink anyway, perhaps chanting “don’t sink three times” might help; it certainly can’t hurt.
  3. Divide cake batter evenly among prepared cake pans and bake until a toothpick comes out clean, 18 to 20 minutes.
  4. Let cool in pans for 10 minutes, then invert onto a wire rack and let cool completely.
  5. Make frosting: In a large bowl using a hand mixer or the bowl of a stand mixer using the whisk attachment, beat butter and 2 1/2 cups powdered sugar. Add remaining lemon juice and zest and heavy cream and beat until combined, then beat in vanilla and salt. (Add remaining 1/2 cup powdered sugar as desired for texture and flavor.)
  6. Place a dab of frosting on cake plate (to keep cake in place) and place parchment strips on each side of the cake plate. Place down first cake and top with frosting, then top with second cake and frost. Repeat with third cake and frost sides.
  7. Garnish with remaining blueberries, lemon slices, and zest and serve.