Loaf Cake

1. Preheat oven to 350F/180C and grease a 9X5 loaf pan.
2. In a medium bowl combine flour, baking powder, and salt. Set aside. In a small bowl or liquid measuring cup mix together the sour cream and lemon juice then set aside. Mix together the blueberries and flour, so each blueberry is evenly coated, set aside.
3. In the bowl of an electric mixer combine sugar, butter, and oil for 3-4 minutes. The mixture should be very thick and fluffy. Add in the first egg and lemon zest and mix until fully combined. Scrape down the bowl then add the next egg.
4.  Gently fold the dry ingredients into the butter mixture. Then gently fold in the sour cream mixture, and finally the blueberries. You don't want to overmix and overdevelop the gluten. 
5. Bake for 55-60 minutes or until a toothpick inserted in the center comes out clean. Let cool on a wire rack in the pan for at least thirty minutes then place the wire rack on top of the cake and gently and carefully flip upside down to invert the cake onto the wire rack to cool completely. 

Lemon Glaze

1. Once the cake is cooled prepare the lemon glaze. In a bowl combine powdered sugar, lemon zest, and 2 tablespoons of lemon juice. Whisk together if the mixture is too thick add a splash of lemon juice at a time until desired consistency. Drizzle on top of the cake. Store cake in an airtight container in the fridge.