Sour Cream Coffee Cake

INGREDIENTS

• 2 cups all-purpose flour, plus additional for dusting pan
• 1 teaspoon baking soda
• 3/4 teaspoon salt
• 1/2 teaspoon baking powder
• 1 cup walnuts, toasted (3 1/2 oz)
• 2 teaspoons cinnamon
• 1 1/4 cups sugar
• 3/4 cup unsalted butter, softened,plus
• 2 tablespoons butter, melted
• 2 large eggs, at room temperature for 30 minutes
• 1 cup sour cream
• 1 teaspoon vanilla