Cool and refreshing blueberry lemon icebox cake is made with only 7 ingredients and can be prepped ahead of time! It’s soft, sweet, and tastes unbelievable.
- 2 teaspoons (6g) cornstarch
- 2 teaspoons fresh lemon juice
- 1 Tablespoon (15ml) warm water
- 2 cups (380g) fresh or frozen blueberries
- 2 Tablespoons (25g) granulated sugar
- 1 teaspoon lemon zest
- 2 cups (480ml) heavy cream or heavy whipping cream
- 1/4 cup (30g) confectioners’ sugar
- 1 Tablespoon fresh lemon juice
- 1 teaspoon lemon zest
- 7–8 full-sheet graham crackers (about 1 standard sleeve)
- optional: additional lemon zest and blueberries for garnish
- Preliminary notes:There are 3 layers of graham crackers, 5 layers of whipped cream, and 2 layers of blueberry sauce. Each layer of graham crackers is about 2 full graham crackers (you can break some up to fit). This recipe yields 4 cups of whipped cream and you will use a little under 1 cup per layer (about ¾ cup).
- Make the blueberry sauce: Whisk the cornstarch, lemon juice, and warm water together in a small bowl until the cornstarch has dissolved. Set aside. Warm the blueberries and sugar together in a small saucepan over medium heat. Stir continuously for 3 minutes until the blueberry juices begin to release. Add the cornstarch mixture and continue to stir for another 2-3 minutes, smashing some blueberries as you go. The mixture will start to thicken. Remove from heat and stir in the lemon zest. Set aside to cool completely (stick in the fridge to speed it up).
- Line a 9×5 inch loaf pan with plastic wrap with overhang over the edges to easily lift the cake out. Set aside.
- Make the whipped cream: Using a hand mixer or a stand mixer fitted with a whisk attachment, beat the heavy cream, confectioners’ sugar, lemon juice, and lemon zest together on medium-high speed until soft peaks form, about 3 minutes.
- Assemble cake: Spread a couple Tablespoons of whipped cream into a very, very thin layer on the bottom of the prepared pan. This will help the bottom layer of graham crackers stick. Layer graham crackers on top. Spread about ¾ cup of whipped cream on top of the graham crackers. Then layer half of the blueberry sauce on top, another ¾ cup whipped cream, another layer of graham crackers, ¾ cup whipped cream, the rest of the blueberry sauce, ¾ cup whipped cream, graham crackers, then the rest of the whipped cream. If desired, sprinkle with additional blueberries and lemon zest.
- Cover with aluminum foil or plastic wrap and place in the freezer for at least 4 hours or overnight.
- Allow to soften in the refrigerator for 1 hour before serving OR at room temperature for 10-15 minutes. Remove the cake from the pan using the overhang on the sides. Cut into slices and serve cold.
- Cover and store leftovers in the refrigerator or in the freezer. If frozen, allow to soften again before eating.
- Make Ahead Instructions: The blueberry sauce and whipped cream can both be made ahead of time. Cover each tightly and refrigerate for up to 2-3 days. The entire cake can be assembled and frozen 2-3 days in advance before continuing with step 7.
- Adapted from Bon Appétit.