In a saucepan, mix dry ... stir until the custard thickens. The mixture should coat ... the vanilla and cream of tartar until soft peaks ... dissolves. Spread over filling and bake at 350°F for 10-15 minutes.
Pour boiling water over butter ... and spread on custard. If the custard sits ... in covered container. Filling will also keep for 4 ... but must be refrigerated.