Soft Sourdough Blueberry Muffins with Sweet Crumble Topping | Perfect Breakfast Bites - Yummy Gusto

Ingredients

• 2 cups (240 g) all-purpose flour
• 1 cup (200 g) granulated sugar
• 2 teaspoons baking powder
• 1 tablespoon corn starch
• ½ teaspoon baking soda
• ½ teaspoon salt
• Zest from half of a lemon
• 1 cup (150 g) blueberries, fresh or frozen
• 8 tablespoons (113 g) butter, melted
• 2 large eggs
• 1 teaspoon (5 g) vanilla extract
• ½ cup (125 g) sourdough discard (starter)
• 3 tablespoons (45 g) plain Greek yogurt or sour cream
• 3 tablespoons (45 g) butter, melted
• ½ cup (100 g) granulated sugar
• ½ cup (60 g) all-purpose flour