1 (1 lb.) pkg. light brown sugar
3 c. granulated sugar
1 (12 oz.) can evaporated skim milk
2 tbsp. butter
1 tsp. cream of tartar
1 (18 oz.) jar chunky peanut butter
2 tsp. vanilla extract

Grease 8 inch square baking pan. In heavy 4 quart saucepan, combine sugars, milk, butter and cream of tartar. Heat to boiling over medium heat. Reduce heat to low. Cook without stirring until mixture reaches 240 degrees on candy thermometer of softball stage. Remove fudge mixture from heat. Stir in peanut butter and vanilla; beat until fudge begins to get firm. Pour into greased pan. Refrigerate until firm; cut into squares.