Preheat the oven to 350?. Add the sugar to a large bowl. Add the zest and use your fingers to rub the zest into the sugar (this brings out all the lemon flavor!).
Add the oil, yogurt, eggs, lemon juice, and vanilla extract to the bowl. Whisk until combined.
Add 2 cups flour, baking powder, baking soda, and salt. Fold together until just combined.
In a small bowl, add the blueberries and additional 1 tbsp of flour. Toss until combined. Add the blueberries to the batter and gently fold in until just combined!
Prepare the cake pans. Grease either two 8" cake pans, or four 4"cake pans. Pour equal amounts of batter into each pan. Transfer to the oven and bake for 25-30 minutes for the small (4") cakes, or 28-35 for the regular (8") cakes -- bake until an inserted toothpick comes out clean.
While the cakes cool, make the frosting. Add the butter to the bowl of a stand mixer and mix for 3-4 minutes. Add powdered sugar, vanilla, and 1 tsp of milk. Mix another 3-4 minutes. If the frosting isn't as smooth as you'd like, add another teaspoon of milk and mix again.
When the cakes are completely cool, spread frosting on the top of one layer, stack another cake on top, then add more frosting on top. Add fresh blueberries and fresh flowers (optional) and enjoy!