For the batter:

• 1/4 cup (1/2 stick) unsalted butter, softened
• 1/2 cup sugar
• 1 egg
• 1 tsp vanilla extract
• 1 cup flour
• 1 tsp baking powder
• Pinch of salt
• 1/3 cup milk
• 1 cup fresh blueberries

For the topping:

• 1/3 cup flour
• 1/4 cup (1/2 stick) unsalted butter, softened
• 1/2 cup sugar
• 3/4 tsp cinnamon

1. Preheat oven to 350 degrees. Fill a muffin tin with paper liners.

2. In a large bowl, beat butter and sugar 1 minute. Add egg and vanilla; beat 1 minute. In a bowl, sift flour, baking powder and salt.

3. Add half the dry ingredients to butter mixture; beat 30 seconds. Add milk, then remaining dry ingredients. Beat 1 minute, or until batter is smooth and fold in half of the blueberries. Pour batter into cups. Sprinkle remaining berries on top.

4. In a bowl, combine topping ingredients. With fingers, rub mixture together until it resembles crumbs. Spread over berries. Bake 20 minutes, or until a toothpick inserted into center comes out clean.