Blueberry Buckle Cake

Ingredients (15)

• For the topping:
• 1/3 cup brown sugar
• 1/2 cup all-purpose flour
• 1 teaspoon cinnamon
• 1/4 cup butter
• For the batter:
• 2 cups all-purpose flour
• 2 teaspoons baking powder
• 1/2 teaspoon salt
• 3/4 cup granulated sugar
• 1/4 cup butter
• 1 large egg
• 1 teaspoon vanilla extract
• 1/2 cup buttermilk
• 2 cups fresh or frozen blueberries