• Preheat the oven to 350℉/176℃. Line a 9x9 baking pan with parchment paper and set aside. Melt the butter and allow it to cool.
  1/4 cup unsalted butter

For the streusel

• Add the flour, white sugar, and softened butter into a bowl. With your hands or a fork, mix until a crumbly streusel forms. Set in the fridge to chill.
  1 cup all-purpose flour, 1/2 cup white sugar, 6 tbsp unsalted butter

For the cake

• In a bowl, add the flour, baking soda, baking powder, and cinnamon. Stir to combine and set aside.
  1 3/4 cups all-purpose flour, 3/4 tsp baking powder, 3/4 tsp baking soda, 1/4 tsp cinnamon
• In another large bowl, add the lemon zest and white sugar. Rub together with your fingers for a minute until combined and the smell of lemon fills the air.
  1 tsp lemon zest, 3/4 cups white sugar
• Add in the eggs and vanilla and whisk for a minute until well combined.
  2 large eggs, 1 tbsp vanilla
• Add the butter, oil, and cottage cheese. Whisk for 1-2 minutes until well combined.
  1/4 cup unsalted butter, 1/3 cup oil, 1 cup cottage cheese
• Combine the dry and wet ingredients until a soft cake batter just forms. Do not over-mix!
• Into the bowl with the blueberries, add 1 tsp of flour and dust the blueberries in it. Then add into the cake batter bowl and mix just until combined and the flour streaks disappear. Do not over-mix!
  1 1/2 cups fresh blueberries
• Transfer into the prepared pan and spread evenly. Sprinkle the streusel on top evenly.
• Bake for 40-50 minutes or until a toothpick inserted in the middle comes out dry. Mine took 45 minutes exactly.
• Allow to cool, slice, and enjoy! This cake is so delicious and easy to bake.