Combine sugar, butter, and evaporated milk in a heavy 2-½ quart saucepan. Bring to a full rolling boil, stirring constantly. Continue boiling over medium heat for 5 minutes, stirring constantly to prevent scorching. Remove from heat. Add the peanut butter, stirring until melted.. Add marshmallow creme and vanilla; beat until well blended.

Spread in a buttered 9 × 13 × 2 – inch pan. Cool at room temperature, then refrigerate. Cut into squares when firm.