Preheat oven to 350°F.
Combine olive oil, lemon juice, lemon zest, honey, eggs and vanilla in a large bowl and whisk well.
Fold in almond flour, baking soda, baking powder and salt, then mix in blueberries.
Let batter sit while you grease a 9" round cake pan then stir once more and transfer to prepared cake pan to bake.
Bake for 35-40 minutes until a toothpick into the center of the cake comes out clean.
To make icing, smash blueberries with a mortar and pestle or blend in a high speed blender with lemon juice. Strain through a fine mesh sieve to collect juice.
Add sifted powdered sugar to a large bowl along with 3 tbsp blueberry juice. If lemon juice was not added already to blender, add lemon juice and stir well until icing is smooth.
Remove cake from the oven and allow it to cool before icing.
