In a small heavy saucepan over medium heat, whisk eggs, egg yolk and sugar together. Slowly mix in lemon juice until blended. Add butter and lemon zest; cook, whisking constantly, until mixture is thickened and coats the back of a metal spoon(170°F). Strain into a small bowl; cool 10 minutes. Refrigerate, covered, until cold.
For the raspberry jam:
In a heavy bottom pan, combine the raspberries, sugar, and lemon juice.
Cook on medium heat until the sugar is dissolved. Then, turn the heat up and let the mixture come to a boil. Let it boil for two minutes stirring constantly on medium-high.
Then, turn the heat to medium-low. The jam should still be simmering but at a low simmer, not bubbling. Mash the raspberries.
Continue to simmer for about 20 minutes more stirring often. The jam will continue to thicken as well as deepen in color as it cools. It should thicken and reach 220°F on a thermometer.
Strain through a sieve into a glass jar or dish to cool.
For the mascarpone whipped cream:
In the bowl of a stand mixer combine the mascarpone cheese, powdered sugar, and lemon zest. Blend until smooth. Turn the mixer on low and slowly add the whipping cream until it's incorporated and starting to thicken. Increase the speed to medium, then high, and beat until medium peaks form. It won't take long.
Transfer ⅓ of the cream to a container with a tight fitting lid and refrigerate until needed. This will be used to "ice" the cake.
Gently fold in ½ cup of lemon curd into the remaining mascarpone mixture. Now you're ready to assemble the icebox cake.
Line a loaf pan with 2 pieces of parchment paper with overhang for easy removal of the cake.
Make the first layer: Line the bottom of the pan with graham crackers, breaking crackers as needed to fill the gaps. Then add the whipped cream mixture, using an offset spatula or spoon to smooth it over the entire surface of the crackers and into the corners. Top with raspberry jam, again spreading into an even layer all the way to the edges. Top the jam with more whipped cream, spread to corners of the pan.
Repeat, starting with graham crackers and ending with whipped cream mixture. Then place a layer of graham crackers over the top.
Cover with plastic wrap. Place in the freezer until completely frozen, 6-8 hours or overnight.
Once frozen, remove the pan from the freezer. Unwrap the top. Then, invert over your serving plate. Carefully peel the parchment from the top and sides of the cake.
Spread the remaining mascarpone whipped cream over the top and sides of the cake. Return to the freezer at least 15 minutes before serving. Garnish and enjoy!
Keyword 4th of july, Cake, Icebox, Lemon, Raspberry