Toffee Sandwich Cookies

In a mixing bowl, cream butter and sugars. Add eggs, one at a time, beating well after each addition. Beat in vanilla. Combine flour, baking soda and salt; gradually add to the creamed mixture. Stir in toffee bits (dough will be stiff). Drop by rounded teaspoonfuls 2 in. apart onto ungreased baking sheets. Bake at 350 degrees F for 10 minutes or until firm (do not brown). In a mixing bowl, combine butter, sugar, vanilla and enough cream to achieve spreading consistency. Spread on the bottom of half of the cookies; top with remaining cookies. ');