Mix flour with baking powder, mix sugar, butter, eggs and the grated zest of 2 lemons and pour into a greased springform pan.
Bake for 1 - 1 1/4 hours at 160 - 175 degrees.
Mix the juice of 3 lemons with 8 tablespoons of sugar until the sugar has dissolved.
Let the cake cool down a bit, then turn it out. Poke holes in the bottom of the cake with a wooden stick and pour the lemon juice into it with a teaspoon. When the juice is well absorbed, turn the cake back over again.
Sprinkle with powdered sugar just before serving.
I bake the cake at about 175 degrees. It is a very old recipe, there was no classification.