For the blueberry sauce:
For the lemon cream:
For the lemon curd
- 3 c fresh or frozen blueberries, plus 1/3 cup extra fresh blueberries, divided
- 1/2 c granulated sugar
- 2 Tbl water
- juice of half a lemon, about 1 Tbl
(purchase 1 c store-bought or see recipe below for homemade), divided
For the pound cake
- zest and juice from 2 lemons, about 1/2 c juice total
- 3/4 c granulated sugar
- 1/4 c unsalted butter, or dairy-free alternative, room temperature
- 2 eggs, (or 1/2 c water plus 2 tbsp Better Batter All-Purpose Flour, whisked together)
- pinch of salt
(purchase 1 9x5 store-bought GF pound cake or see recipe below for homemade)
- 1 1/2 c granulated sugar
- 1/2 c (1 stick) unsalted butter, at room temperature
- 1 vanilla bean, scraped (or substitute 2 tsp vanilla extract)
- 3 eggs
- 1/2 c sour cream
- 1 1/2 c (6 oz) Better Batter All-Purpose Flour
- 1/2 tsp baking soda
- 3/4 tsp salt
- Cooking spray
Plan ahead! This dessert, once fully assembled, needs at least 8 hours to harden completely. This is best made a day ahead of when you want to serve it. During assembly time, notice the extra freezer time needed to help firm up layers before adding to the cake.
Make the lemon curd (homemade is optional, but super easy!).
In the bowl of a stand mixer or using a large bowl and a handheld electric mixer, beat together the lemon zest and butter or dairy-free alternative until light and fluffy. Add the sugar and salt and beat well. Add the eggs one at a time (or the water and flour slurry in two parts) and then add the lemon juice. The mixture will look curdled. Transfer the curd mixture to a medium saucepan and place over medium-low heat. Whisk constantly as the curd comes to a simmer and begins to thicken. Remove from the heat and pour into a bowl to cool. Place a piece of plastic wrap directly on the surface of the cooked lemon curd so a thick skin does not form. Then cover the bowl with a second piece of plastic wrap and chill for at least two hours.
Make the pound cake by following these directions.
Preheat the oven to 375 degrees. Line a 9×5 loaf pan with parchment paper and lightly spray the parchment paper. Set aside. Make the cake.
In a stand mixer, or using a large bowl and handheld electric mixer, beat together the butter and sugar on medium speed until light and fluffy, about four minutes. Mix in the sour cream and vanilla bean seeds (or vanilla extract) for an additional two minutes. Add the eggs, one at a time, and beat well to incorporate. Add the flour, baking soda, and salt and mix together until just combined. Pour batter into prepared pan. Bake.
Bake the pound cake for 50-60 minutes or until a toothpick inserted in the center comes out clean. Be sure to rotate the pan halfway through the baking time and I lightly tented the cake with foil halfway through the baking time so the top wouldn’t overbrown. Transfer to a wire rack to cool in the pan for 20 minutes, then carefully pull on the parchment paper to release the cake from the pan. Cool cake completely. When cooled, for a prettier cake presentation, carefully trim away the browned edges and slice the cake into long, flat layers. You can use up to three layers for the icebox cake.
Make the blueberry sauce.
Combine 3 cups of fresh (or frozen) blueberries with 1/3 cup granulated sugar and 2 tablespoons water in a deep saucepan. Heat on medium until the mixtures begins to boil. Reduce the heat slightly to maintain a simmer, and cook until the blueberries pop and the sauce thickens, about 5 minutes. Add the lemon juice and cook until the mixture is almost reduced by half, about 10 minutes. You will need 1 1/2 cups of sauce total. Remove from the heat and cool. Refrigerate until ready to use. (Keep the extra ⅓ cup of fresh blueberries ready - they are added at the end.)
Make the lemon cream filling.
In the bowl of a stand mixer combine the mascarpone cheese, powdered sugar, and lemon zest, blending until smooth. Turn the mixer on low and slowly add the whipping cream until it's incorporated and starting to thicken, I used by whisk attachment for this part. Increase the speed to medium, then high, and beat until medium peaks form. Transfer 1/3 of the cream to a container with a tight fitting lid and refrigerate until needed. This will be used to ice the cake later on. Gently fold in 1/2 cup of lemon curd to the remaining cream filling.
Line a 9x5 loaf pan with a few layers of plastic wrap, making sure to have lots of overhang on all sides. To the bottom of the plastic wrap-lined pan, add a layer of pound cake, cutting to fit as needed. Spread 1/4 of the lemon cream over the pound cake, using a spoon to smooth the surface. Freeze these layers 5-10 minutes. Next, layer 1/2 cup blueberry sauce over the lemon cream, spreading carefully with a spoon before returning the pan to the freezer for 10 minutes. Add 1/4 c leftover lemon curd over the blueberry sauce then top with 1/3 of the remaining lemon cream. Smooth with a spoon and top with another layer of pound cake.
Add a second set of layers in this order to finish up your icebox cake. Over the second layer of pound cake, add half of the remaining lemon cream, 1/2 cup blueberry sauce, and the remaining lemon curd, freezing between layers as needed. Finish off with the last of the lemon cream and a final layer of pound cake. Pull the plastic wrap up and over the top to cover the final layer of pound cake. Freeze the entire cake, pan and all, at least 8 hours or overnight. You should have about 1/2 cup of blueberry sauce left for garnish at serving time. Add the fresh blueberries to this sauce and refrigerate.
When ready to serve, remove the plastic wrap and invert the cake onto a serving platter. Peel off the plastic wrap. You may need to re-whisk the the reserved mascarpone cream until soft peaks form again. Spread the top and sides of the cake with the reserved cream. Re-freeze the entire cake at least 15 minutes or until ready to serve. Slice into thick pieces and plate onto dessert plates, adding a spoonful of the reserved blueberry sauce on top. Freeze leftover cake, wrapped in plastic wrap.
Adapted from Saving Room for Dessert blog