Delicious Blueberry Walnut Mascarpone Muffins recipe

Ingredients

• 1/2 cup unsalted butter, room temperature
• 3/4 cup granulated sugar
• 1 large egg, room temperature
• 1 tsp pure vanilla extract
• 1/2 cup mascarpone
• 2 1/2 cups flour plus 2 tbsp unbleached all-purpose flour, divided
• 1/2 cup whole milk
• 2 tsp baking powder
• 1 tsp kosher salt
• 2 cups fresh blueberries
• 1/2 cup toasted walnuts, chopped
• raw (course grain) sugar for topping