Jumbo Fluffy Walnut Apple Muffins

Ingredients

• 2 cups all-purpose flour
• 1 cup granulated sugar
• 2 teaspoons baking powder
• 1/2 teaspoon baking soda
• 1/2 teaspoon salt
• 1 teaspoon ground cinnamon
• 1/2 teaspoon ground nutmeg
• 1/2 cup unsalted butter, melted
• 1 cup buttermilk
• 1 teaspoon vanilla extract
• 2 large eggs
• 1 cup peeled and finely chopped apple
• 1/2 cup chopped walnuts