1 stick plus 2 tablespoons unsalted butter at room temperature
1/4 cup granulated sugar
1/2 cup firmly packed brown sugar
1 large egg
1/2 teaspoon vanilla extract
1 cup plus 2 tablespoons all-purpose flour
1/2 teaspoon baking soda
1/4 teaspoon salt
6 ounces dark chocolate, broken into bite-sized pieces
1 rounded cup salted roasted pecan halves