Line an 8-inch baking pan with foil with the foil extending up over edges of pan.
Microwave 1/2 cup sweetened condensed milk, peanut butter and white baking chips in medium microwave-safe bowl on HIGH 1 minute or until melted and smooth when stirred. Stir in 1/2 teaspoon vanilla and almond extract until blended. Stir in peanuts if desired.
Microwave remaining sweetened condensed milk, chocolate chips and salt in medium microwave-safe bowl on high 1 minute or until melted and smooth when stirred. Stir in remaining 1/2 teaspoon vanilla until blended.
Spoon the peanut butter mixture into the pan, smoothing out into an even layer. Spoon the chocolate mixture on top of the peanut butter layer, smoothing with a spatula. Pat evenly to flatten top surface.
Chill fudge for at least one hour and cut into squares to serve.