My Best Blueberry Muffins

Bahan-bahan (12 porsi)

• 1/2 cup (100g) packed light or dark brown sugar
• 1/2 cup (67g) chopped walnuts (or pecans)
• 1 teaspoon ground cinnamon
• 1 and 3/4 cups (219g) all-purpose flour (spooned & leveled)
• 1 teaspoon baking soda
• 1 teaspoon baking powder
• 1/2 teaspoon salt
• 1/2 cup (8 Tbsp; 113g) unsalted butter, softened to room temperature
• 1/2 cup (100g) granulated sugar
• 1/4 cup (50g) packed light or dark brown sugar
• 2 large eggs, at room temperature
• 1/2 cup (120g) sour cream or plain/vanilla yogurt, at room temperature
• 2 teaspoons pure vanilla extract
• 1/4 cup (60ml) milk, at room temperature
• 1 and 1/2 cups (210g) fresh or frozen blueberries