In a large bowl, cream butter and sugar. Beat in egg and lemon extract. Gradually add the flour. Press into a greased 15x10x1-in. baking pan; set aside.
In a heavy saucepan, melt butter and chocolate until smooth. Remove from the heat; cool slightly. In a bowl, beat eggs, sugar and vanilla, Beat in cooled chocolate mixture, flour and salt. Pour over the crust.
Bake at 350° for 20-22 minutes or until a toothpick comes out clean. Cool completely on a wire rack. Drizzle candy coating over bars. Cool for 20 minutes before cutting.