Cream butter and shortening; gradually add sugars, beating well at medium speed of an electric mixer. Add egg; beat well.

Combine flour, soda, and salt; add to creamed mixture, mixing well. Stir in vanilla. Stir in white chocolate and macadamia nuts. Chill dough 1 hour.

Drop dough by 2 Tablespoonfuls, 3 inches apart, onto lightly greased cookie sheets. Bake at 350 degrees for 12 to 14 minutes (cookies will be soft). Cool slightly on cookie sheets; remove to wire racks to cool completely. Yield 1 1/2 dozen