Lemon Meringue Bars

Heat oven to 350 °F. Line a 13 x 9-in. baking pan with foil, letting foil extend above pan at both ends. Coat foil with nonstick spray. Beat butter, shortening and both the light-brown and granulated sugar in a large bowl with mixer on medium speed until well mixed. Beat in yolks, vanilla and salt until blended. On low speed, gradually add flour; beat until just blended. Pat dough over bottom and slightly up sides of pan. Bake 15 minutes or until pale golden and firm when gently pressed. Meanwhile make Filling: In a food processor or with mixer, process or beat ingredients until blended. Pour over hot crust. Bake 20 minutes until filling sets slightly. Meringue: Beat egg whites in a medium bowl with mixer on high speed until foamy. Add vinegar; beat until soft peaks form. Beat in sugar, about 1 Tbsp at a time. Beat 5 minutes more or until shiny, stiff peaks form when beaters are lifted. Spread the meringue over Filling to cover, making swirls with back of a spoon. Bake 15 to 18 minutes until peaks of meringue are golden brown. Cool completely on a wire rack. Lift foil by ends onto cutting board; cut in bars. These are best served the day they're made.