Praline Ice Cream Cake

Ingredients (14)

• 1 cup packed brown sugar
• 1/2 cup sour cream
• 2 tablespoons plus 1/2 cup butter, divided
• 2 teaspoons cornstarch
• 1 teaspoon vanilla extract, divided
• 2 cups vanilla ice cream, softened
• 2 eggs
• 1-1/2 cups all-purpose flour
• 1 cup graham cracker crumbs
• 2/3 cup sugar
• 2-1/2 teaspoons baking powder
• 1/2 teaspoon salt
• 1/2 cup chopped pecans, toasted
• Whipped cream, optional