For the curd: place a fine sieve over a medium bowl. In a heavy medium saucepan, combine the butter, granulated sugar, lemon juice and zest. Stir over medium-high heat until the sugar dissolves and the mixture just comes to a simmer. Whisk the eggs in another medium bowl to blend. Gradually whisk in the hot lemon mixture. Return the mixture to the same saucepan. Cook over medium-low heat, stirring constantly, until the curd thickens (do not boil). Immediately pour the curd through the sieve, pressing all the curd through. Cool slightly. Press plastic wrap on the surface of the curd and refrigerate until cold, preferably overnight.

For the cake: preheat the oven to 350°F. Butter 2 8-inch cake pans. Line the bottoms of the pans with parchment paper rounds and butter the parchment. In a small bowl, combine the almond meal, baking soda and cinnamon and mix to blend. In a large bowl, combine the egg yolks, ⅓ cup of the granulated sugar, lemon zest and lemon juice and whisk until smooth.

In the bowl of an electric mixer, place the egg whites. Using medium speed, beat until frothy. Add the salt and cream of tartar and beat on medium-high speed until the whites form soft peaks, about 2 minutes. Gradually add the remaining ⅓ cup of granulated sugar 1 tablespoon at a time, beating until stiff peaks form. Using a wooden spoon, stir the almond mixture into the yolks (the mixture will be very thick). Add about ⅓ of the whites and mix in to lighten. Fold in the remaining whites in 2 additions. Divide the batter between the 2 prepared pans.

Bake the cakes until brown, springy in the center, and a tester inserted in the center comes out clean, about 25 minutes. Transfer the pans to wire racks. Using a small, sharp knife, cut around the cake edges. Cool completely in the pans.

Transfer ⅔ cup of the curd to a small bowl and reserve to spread over the cake.

For the lemon whipped cream: In a medium bowl, combine the cream and powdered sugar. Beat until peaks form. Fold ⅓ of the whipped cream into the remaining lemon curd to lighten. Then fold in the remaining cream.

Place 1 cake layer rounded side up on a platter. Spread the reserved lemon curd over the top of the cake. Mound a few big spoonfuls of the whipped cream over the curd. Top with the second cake layer, rounded side up. Mound the remaining whipped cream over the top of the cake. Place a few toothpicks in the top of the cake, and cover with plastic wrap. Refrigerate until ready to serve. Garnish with fresh berries before serving.