1 1/2 c. Lemon Olive Oil
1/2 c. cold water
1 1/2 c. sugar
2 eggs, beaten
1/2 c. sour cream or plain yogurt
1 tsp. vanilla extract
2 c. (250 g.) flour
3/4 tsp. salt
1 1/2 tsp. baking soda
1 lb. unsalted butter at room temperature
1 1/2 c. powdered sugar
4 Tbsp. Blueberry Balsamic
Preheat oven to 350F. Mix together Lemon Olive Oil and water together. Add sugar and stir until dissolved. Add the sour cream (or yogurt), beaten eggs, vanilla and whisk together. Add the flour and sprinkle the salt and baking soda over the flour and whisk well until incorporated. The batter will be somewhat thin; you will be able to pour it in the cupcake liners. Prepare muffin pans with cupcake liners. Pour (or ladle) the batter in a measuring cup with a spout (or a similar vessel with a pouring spout) and pour the batter into the cupcake liners 3/4 of the way full. Bake for 18-20 minutes, until a toothpick inserted into the middle of a cupcake comes out clean. Cool cupcakes on a wire rack for 10 minutes. Remove cupcakes from pan and let cool completely before frosting.
Using a stand mixer or an electric hand mixer beat the butter well, about 1 minute with a stand mixer or 2 minutes with a hand mixer. Add about half of the powdered sugar and the Blueberry Balsamic, then beat well, but start off on low until the sugar is mixed in so it doesn't go flying all over the kitchen. Once it is incorporated add the rest of the sugar, start on low again then increase to high speed and beat until very fluffy, about 3 minutes in a stand mixer or 5 with a hand mixer. If you want the frosting more stiff add more sugar; if you want it more loose, add a little milk.
Use right away. If you aren't going to use it right away keep it at room temperature until you do, for a few hours anyway. If you aren't going to use it until the next day, refrigerate it. The next day you will first need to bring it to room temperature then beat it again. Refrigerating it will make it hard since it is mostly butter.
This frosting freezes well for at least 6 months. Make sure it's wrapped very well so air doesn't get into it. When ready to use, bring it to room temperature and then beat again.