Soften pie crust as directed on box. Heat oven to 350°F. Place pie crust in 9-inch glass pie plate as directed on box for One-Crust Filled Pie. In blender, place all filling ingredients. Cover; blend on high speed until smooth. Pour into crust-lined plate. Bake 1 hour 10 minutes or until knife inserted in center comes out clean. Cool on cooling rack.
In small saucepan, stir together brown sugar, 1/2 cup half-and-half and 1/2 cup butter. Heat to boiling over medium heat. Cook and stir 1 minute. Remove from heat; stir in pecans and 1/2 teaspoon vanilla. Cool completely; serve sauce over slices of pie.