Once cooled off, remove the cake from the spring form pan by releasing the sides first, then remove the bottom.
Very carefully slice a thin layer off of the top to remove the top crust and expose the inside of the cake.
Extra carefully slice the cake in half using a serrated knife.
Place the bottom part on a plate or cake stand.
Using a small spatula spread the chilled lemon curd on top of the olive oil cake.
Spoon half of the mascarpone filling on top, or as much as you feel comfortable working with. If it seems like too much for you, simply save some for later use. Then top it with half of the blueberries from the blueberry sauce and some of the fresh blackberries. Reserve as much of the liquid from the blueberry sauce as possible for the next layer.
Add the next olive oil cake layer and spoon all the remaining blueberries with the sauce on top. Add the remaining whipped mascarpone (or however much you feel comfortable working with) and with the back of a spoon or spatula rustically spread it over the top. Place the fresh blackberries all over the top, reserving some to decorate the sides of your olive oil cake.
Garnish your lemon olive oil cake with edible flower blossoms and enjoy chilled.