• Preheat the oven to 350℉. For easy removal of the cake, place parchment paper on the bottom and 2 sides of the pan. Gently grease the other two sides and then set aside. Lightly wash the blueberries and lightly pat them dry, don't dry them completely though as it's easier for the flour to stick to them if they are wet.
  1 1/2 cups fresh blueberries

For the streusel

• In a medium sized bowl, add flour, sugar, and softened butter. Using your hands, mix this until crumbly and combined. Set aside while you make the muffin batter.
  3/4 cup all-purpose flour, 5 tbsp butter, 1/3 cup white sugar

For the cake

• In a medium sized bowl, add in flour, baking soda, baking powder, cornstarch, and salt. Stir to combine and set aside.
  2 cups all-purpose flour, 1 tsp baking soda, 1 tsp baking powder, 1/4 tsp salt, 1 tbsp cornstarch
• In a large bowl, add lemon zest and white sugar. Using your hands, rub the two ingredients together for about a minute. This helps release the lemon zest fragrance and combine it with the sugar well.
  1 tbsp lemon zest, 3/4 cups white sugar
• Into the same bowl, add in the oil, eggs, vanilla, and buttermilk. Continue mixing until smooth.
  1/2 cup oil, 2/3 cups buttermilk*, 1 tbsp vanilla, 2 eggs
• Mix in the dry ingredients and using a spatula, gently fold until a batter forms. Do not over-mix!
• Gently toss the blueberries in 1-2 tsps of flour before adding them into the mixing bowl. This will help prevent them from sinking to the bottom of the cake. Then add into the bowl and mix in a few times.
  1 1/2 cups fresh blueberries
• Spread the batter into the prepared pan evenly and sprinkle the streusel evenly on top.
• Bake for 40-50 minutes. It really depends on your oven, but after 35 minutes I would start checking with a toothpick to see if it's ready! A toothpick should come out clean.
• Allow to cool, slice, and enjoy! This easy blueberry cake is soo good! It stays good on the counter for a day in an airtight container, and in the refrigerator for 5 days!