Best-Ever Blueberry Muffins

Ingredients

• 1 and 1/2 cups flour
• 3/4 cup sugar
• 1 teaspoon Haddar Baking Powder
• 1 teaspoon Gefen Baking Soda
• 1/2 teaspoon salt
• 1 cup sour cream
• 1/2 cup (1 stick) butter, melted
• 4 tablespoons milk
• 2 teaspoons Gefen Vanilla Extract
• 1 egg
• 1 and 1/4 cups blueberries
• 1/2 cup brown sugar, packed
• 1/2 cup flour
• 2 teaspoons Gefen Cinnamon
• 1 tablespoon Gefen Vanilla Sugar
• 4 tablespoons butter