Heat oven at 350F - 180°C.
Butter and flour an 8 inches (20 cm) springform pan and set aside.
In the bowl of a stand mixer, whip whole eggs and sugar until fluffy.
Add sifted ricotta cheese and whip to combine.
Then add oil and lemon zest and mix until completely incorporated.
By hand, with a whisk, add sifted flour and mix to combine.
Pour half the batter in the pan, spread evenly with a spatula, cover the whole surface with blueberries and pour the remaining batter.
Smooth the surface and cover with the remaining blueberries.
Bake for about 50 minutes (check the cake is done with a wooden skewer).
Let completely cool and dust with icing sugar.