Zest the lemon & squeeze the juice. Set aside.
Oil the tarte baking tin.
Preheat the oven to 160° C fan.
Mix flour & baking powder.
Mix sugar, salt & eggs with the egg whisk until smooth.
Add the olive oil & whisk.
Add the flour mix - use a sieve to avoid lumps - & whisk.
Add the lemon juice & mix.
Fold in the lemon zest.
Pout the mess into the tarte baking tin.
Distribute the blueberries all over the cake. When baking the blueberries will sink to the bottom.
Let it bake in the oven for at least 30 min. Put a sheet of baking parchment under the tarte baking tin.
Make the famous test with the wooden pin .. and add another 5 min if necessary.
Let the cake rest for about 10 min on a cooling rack. Then turn it upside down & remove carefully the tarte baking tin with the loose bottom. (Maybe it's necessary to loosen the cake from the rim with a wooden pin before...)
When at room temperature add some icing sugar with a small sieve on top.