Lemon Blueberry Coffee Cake

Ingredients

• nonstick cooking spray, for greasing
• ¼ cup granulated sugar
• ¼ cup light brown sugar
• ¼ cup all purpose flour
• ¼ cup unsalted butter, cut into small pieces, room temperature
• 1 cup fresh blueberry
• 1 ½ cups all purpose flour, divided, plus 1 tablespoon
• 1 ½ teaspoons baking powder
• ½ teaspoon kosher salt
• ½ cup unsalted butter, room temperature
• ¾ cup granulated sugar
• 2 large eggs, room temperature
• 1 teaspoon vanilla extract
• 3 tablespoons fresh lemon juice
• 1 tablespoon lemon zest
• ½ cup whole milk, room temperature
• 1 ½ cups powdered sugar
• 1 teaspoon lemon zest
• 2 tablespoons lemon juice
• 1 tablespoon whole milk, plus more as needed