Beat eggs, sugar and the grated zest of one lemon until creamy. Add flour and baking powder alternately with the orange juice. Add melted butter. Pour the mixture into a well-greased cake pan and bake at 180 degrees for about 1 hour.
Turn out hot onto a wire rack.
While the cake is baking, cook the glaze: Grate the lemon zest, stir through with the juice of one lemon, mix well with the powdered sugar. Poke holes in the hot cake with a knitting needle, keep applying the glaze with a brush until it is all used up.
The lemon zest on the cake looks a bit strange, but the flavor is unique. You can also sprinkle a little powdered sugar on top.