Chai-Spiced Banana Bread - Once Upon a Chef

Ingredients

• ½ cup (1 stick) unsalted butter, softened
• 1 cup granulated sugar
• 2 large eggs, (at room temperature)
• 1½ cups all-purpose flour, (spooned into measuring cup and leveled-off)
• 1 teaspoon baking soda
• ¾ teaspoon ground cardamom
• ¾ teaspoon cinnamon
• ¼ teaspoon ground ginger
• ¼ teaspoon allspice
• ¾ teaspoon salt
• 1 cup mashed very ripe bananas, (from 2 to 3 bananas)
• ½ cup sour cream
• 1 teaspoon vanilla
• ½ cup chopped walnuts ((optional))