Walnut Squares

Ingredients

• 2 cups unbleached flour
• 1/3 cup granulated sugar
• 1/4 teaspoon salt
• 1/4 teaspoon baking powder
• 1/2 cup (1 stick) cold unsalted butter, cut into 8 pieces
• 2 large eggs
• 2/3 cup light corn syrup
• 1-1/4 cups packed light brown sugar
• 1/4 cup (1/2 stick) unsalted butter
• 1/2 cup whipping cream
• 2 teaspoons vanilla
• 1 tablespoon dark rum
• 4 cups coarsely chopped walnuts or pecans