Peanut Butter Cocoa Fudge

2 cups sugar
2 cups light brown sugar
1 teaspoon salt
1/2 cup cocoa powder
1 1/3 cups milk
1/4 cup butter
3/4 cup peanut butter
2 teaspoons vanilla extract

Line a 8 x 8 x 2-inch square baking pan with lightly buttered waxed paper or aluminum foil. Set aside. In a saucepan, stir together the sugars, salt, cocoa powder, milk, and heat until sugar is dissolved. Add the butter and cook to 238* F (115*C) on a candy thermometer. Pour out of the pan into a mixing bowl to cool slightly and, with a paddle attachment (or use a heavy wooden spoon), stir in the peanut butter and vanilla. Continue beating to cool and stiffen the fudge until it starts to lighten and loses its gloss. Quickly spread the fudge into the prepared pan. Cool completely before cutting into squares. Makes 20 pieces.