Preheat your oven: to 180°C / 350-375°F / Gas Mark 4-5.
Prepare tin: use butter to grease a 22.5 cm (8.8 inch) round cake tin, then line it on the base and sides with parchment paper, then set side.
Eggs: crack the eggs one by one into a large jug and then use a fork to give them a quick whisk.
Lemon zest: use a microplane zester to zest the lemons and then transfer the zest into a small bowl and set aside.
Butter and sugar: add the butter to a large mixing bowl and then use electric beaters to cream until it is pale and fluffy. Then gradually add in the sugar and keep beating till combined.
Almond meal and lemon zest: add the almond meal to the cake batter, followed by the lemon zest and continue to use the beaters to consistently combine.
Whisked eggs: pour the whisked eggs into the batter and use the electric beaters to combine.
Polenta: next add the polenta to the batter and mix until it is consistently combined.
Cake tin: use a spatula to transfer the wet cake batter and into the lined tin and use the back of a spoon to smooth the mixture evenly across the pan.
Oven bake: place the cake into the oven on the middle shelf and bake it for 35 to 40 minutes. Then use a skewer inserted directly down into the cake and pull it out. If there is wet batter, bake it for a little longer, if the skewer comes out with only crumbs, then it is done.
Cool: place the cooked polenta cake onto a wire rack and let cool for 5 or 10 minutes. Then remove the cake from the tin and flip the cake bottom side up. Then discard the baking paper.
Lemon syrup: juice the 3 lemons that you earlier zested, then add the juice to a heatproof jug. Add ¾ cup of sifted icing sugar, stir and heat on high in 3 x 30 second intervals, stirring between each interval.
To serve: dust the polenta cake with icing sugar and leftover lemon zest. Drizzle lemon syrup over the top (optional).