Lemon Mascarpone Layer Cake

[nverland]

Lemon Mascarpone Layer Cake
Prep: 20 mins Cook: 25 mins Total: 45 mins Servings: 10 to 12 servings

Ingredients

For the Sponge Cakes:
6 large eggs (separated)
7 tablespoons (3 ounces) sugar plus
7 tablespoons (3 ounces) sugar
1 3/4 cups (6 ounces) sifted cake flour

For the Lemon Syrup:
1/2 cup (3 1/2 ounces) sugar
1/2 cup (4 ounces) water
1/4 cup (2 ounces) lemon juice (freshly squeezed)

For the Mascarpone Filling:
2 1/2 cups (20 ounces) heavy whipping cream
7 tablespoons (3 ounces) sugar
1 pound mascarpone
1 cup lemon curd (plus 1 1/2 cups for layering and garnish)


Steps

1 - Preheat the oven to 375 F. Position oven racks in the lower and upper thirds of the oven.
2 - Make the sponge cakes: Place the egg yolks and 7 tablespoons of the sugar in the bowl of a stand mixer fitted with the whisk attachment and whip on high speed until the mixture is thick and very light in color, 4 to 5 minutes. Set aside while you whip the egg whites.
3 - In a clean bowl with a clean whisk attachment, whip the egg whites on medium speed to soft peaks. With the mixer running, gradually add the remaining 7 tablespoons of sugar and continue beating until the egg whites hold firm peaks. Fold a third of the egg whites into the beaten yolks, then sift half of the flour over the top and gently fold it in. Repeat. Fold in the last of the egg whites until no streaks of white remain.
4 - Divide the batter evenly between the prepared pans and bake for 18 to 22 minutes, until the top is golden, firm to the touch, and a toothpick inserted into the center comes out free of crumbs. Remove from the oven and place on a rack to cool completely.
5 - Make the lemon syrup: Place the sugar and water in a small saucepan and heat, stirring occasionally, until the sugar has completely dissolved and the liquid is clear. Remove from the heat and cool completely. Stir in the lemon juice.
6 - Make the mascarpone filling: Place the cream and sugar in a bowl and whip to soft peaks. Refrigerate. Place the mascarpone and 1 cup of the lemon curd in a bowl and stir until blended—it should be the consistency of pudding. Gently fold in the whipped cream until the mixture is homogeneous and thick. If the mixture becomes overworked, it will look grainy or separated. If this happens, stir in several tablespoons of cream with a rubber spatula—stir just until the mixture has smoothed out again.
7 - Unmold the cakes: Run the thin, flexible knife or spatula around the edge of the pan to loosen a cake. Turn the pan upside down and give it a sharp rap on the table to release (don't worry, these cakes are very sturdy). Turn the cake right side up, leaving the parchment paper attached. Repeat with the remaining cake. Level the cakes, if necessary. Using the serrated knife, slice each cake horizontally into 2 layers. Set aside one of the bottom layers to use last, and remove the parchment from the other layer.
8 - Assemble the cake: Place a cake layer, cut-side up, on the cake cardboard or serving plate. Brush the cake with 1/4 of the lemon syrup. With the icing spatula, spread 1/4 of the mascarpone filling on top. Place 3 level tablespoons of the remaining lemon curd on top of the filling and spread evenly to the edge. Place a second cake layer on top, cut-side up, and repeat with lemon syrup, mascarpone filling, and lemon curd. Place third layer on top, cut-side up, and repeat.
9 - Top with the last cake layer, placing it bottom up (cut-side down). Remove the parchment paper. Voila!—a crumb-free surface for frosting. Moisten it with the remaining lemon syrup. Use the cleaned icing spatula to spread the mascarpone frosting mixture over the cake, spreading it quite thinly on top with more on the side, making sure to leave some for piping.
10 - Finish and serve the cake: Spoon the piping mascarpone into the pastry bag and pipe rosettes over the entire top of the cake, starting around the outside edge and working your way to the center. Put a few tablespoons of the remaining curd into a resealable plastic sandwich bag and squeeze it into one of the corners. Snip off the corner and pipe a center of lemon curd into each of the rosettes. Refrigerate for at least 4 hours before serving so the flavors and textures have a chance to meld. To serve, slice with a thin, sharp knife.

Tips
This cake can be made up to three days in advance and will store well wrapped in plastic at room temperature. Leave the parchment paper on to help stabilize the layers.
The individual sponge cakes can be frozen—double-wrapped in plastic, each inside a resealable plastic freezer bag—for up to eight weeks. To thaw, unwrap the cakes and defrost them at room temperature for one hour.
The lemon syrup can be made up to one week in advance and you can make the lemon curd three days in advance.
Once cut, there is no need to wrap the whole cake with plastic. Just press a piece of plastic wrap firmly against the cut surface to keep it fresh. The cake will keep refrigerated for three to four days.

Recipe Variation
This particular recipe uses a pound of mascarpone, but even a small amount—a few tablespoons for each cup of cream—will still add richness to your dessert. Adjust the portion of cheese to suit your dietary goals.