mimosa balls and crystallised violets, to decorate
Preheat the oven to 180C/Gas 4/fan oven 160C. Butter and line the base of a shallow oblong tin (about 18x28cm/7x11in) with baking parchment. Tip all the cake ingredients into a large mixing bowl and beat for 2-3 minutes, until the mixture drops easily off the spoon.
Spoon the mixture into the tin and smooth the surface with the back of a spoon. Bake for 30-40 minutes, until golden and firm to the touch. Meanwhile, make the icing: beat together the lemon juice and sugar, pour the mixture evenly over the cake while it is still hot, then leave to cool.
Cut the cake into 15 squares. Top each one with a crystallised violet and mimosa ball.