Butter a 9 inch cake pan. Line the bottom of the pan with waxed paper and butter the paper. In a food processor, process the almonds with 2 tablespoons of sugar, until finely ground. Transfer to a medium bowl and set aside.
In the processor, process the egg yolks, 2 tablespoons of sugar, the lemon zest, cinnamon and salt together for 1 minute. Add to the almond mixture and stir until blended. Set aside.
Using an electric mixer, beat the egg whites on low speed until foamy, then increase to medium speed and beat until soft peaks form. Gradually beat in the remaining sugar and continue beating until stiff, glossy peaks form. Fold the egg whites into the almond mixture. Pour the mixture into the prepared pan and smooth the top.
Bake for 30-35 minutes, or until a toothpick inserted in the centre comes out clean.
Remove from the oven and let cool completely on a wire rack. Unmold onto a plate and remove the paper. Dust with confectioners' sugar. Cut into wedges and serve with fresh berries and a dollop of whipped cream.