Walnuts, Almonds and Pistachios: Year-Round Favorites at their Peak in Winter

Ingredients

• 1 1/2 cups flour
• 1/4 cup sugar
• 1/4 cup butter, cut into 1/2-inch chunks
• 1 large egg
• 2 tablespoons butter, melted and cooled
• 1/2 cup firmly packed light brown sugar
• 2 large eggs
• 1/2 cup Cointreau (optional)
• 1-inch piece of vanilla bean
• 1 1/2 cups walnut and almond meats, coarsely chopped and lightly toasted