Preheat oven to 325 degrees. Greast a 9-inch springform pan and line the base with parchment paper.
Melt the chocolate in a double boiler until melted. Remove from the heat and let cool for about 10 minutes.
Beat together the butter and half the sugar until smooth, then beat in the egg yolks one at a time. Stir in the vanilla and melted chocolate. Add the flour and the almonds; stir gently.
In a separate bowl whisk the egg whites until foamy, then whisk in the remaining sugar slowly, until thick and glossy peaks have formed. Fold a small amount at a time into the chocolate mixture. Pour the batter into the prepared pan and bake for about 35 minutes, until risen and golden.
Let the cake cool in the pan for about 10 minutes, then remove the outside ring and let the cake cool on the base.
For the frosting, beat the mascarpone cheese, confectioners sugar, lemon extract and lemon zest.
Puree 10 strawberries, adding 1/2 cup of sugar.
Slice 4 of the strawberries for garnishing the top of the cake.
To serve, pour the strawberry puree over the top, letting it spill down over the sides. Arrange the strawberries on top of the cake, around the outer side. Place a beautiful flower in the center.