For cake: Preheat oven to 350 degrees

Beat yolks with mixer until thick and lemon colored. Add sugar gradually, beating continuously. Add dry ingredients, sifted together, alternately with boiling water. Add vanilla and beat well.. In another bowl, beat egg white whites until stiff peaks form; fold into batter. Pour into a sheet pan and bake for approximately 20 minutes. Cool on rack. Cut into squares.

Frosting: With mixer cream butter; add sugar and vanilla. Frost bars on all sides. Roll in crushed peanuts.