Preparation Steps

• Preheat oven to 350°F (175°C). Grease and flour a 9x13 inch baking pan.
• In a medium bowl, whisk together flour, baking powder, and salt for the batter. Set aside.
• In a large bowl, cream together softened butter and granulated sugar until light and fluffy.
• Beat in eggs one at a time, then stir in vanilla extract and lemon zest.
• Alternately add the dry ingredients and milk to the wet ingredients, beginning and ending with the dry ingredients. Mix until just combined.
• Gently fold in the fresh blueberries.
• Spread the batter evenly into the prepared baking pan.
• In a separate bowl, combine flour, brown sugar, granulated sugar, and cinnamon for the streusel topping. Cut in the cold butter until the mixture resembles coarse crumbs.
• Sprinkle the streusel topping evenly over the batter.
• Bake for 35-45 minutes, or until a toothpick inserted into the center comes out clean.
• Let cool in the pan for 10 minutes before serving.