Ultimate Irish Apple Cake

INGREDIENTS

• 4 tablespoons butter, softened (room temperature)
• 1 cup granulated sugar
• 1 egg, beaten (room temperature)
• 4 granny smith apples, cored, peeled and diced (2 cups)
• 1/4 cup chopped walnuts
• 1 teaspoon vanilla extract
• 1/2 teaspoon baking powder
• 1/2 teaspoon baking soda
• 1/2 teaspoon salt
• 1/2 teaspoon ground cinnamon
• 1/2 teaspoon ground nutmeg
• 1 cup all-purpose flour