Cream butter and sugar. Beat in eggs, vanilla and Amaretto.
In another bowl - combine flour, baking powder and salt. Add this to the creamed mixture until blended. Fold in the nuts and white chocolate chips.
Divide the dough in half. On a greased and floured baking sheet, pat the dough into two logs.
Bake in the middle of a 325 degree F. oven for 25 minutes, or until lightly browned.
Remove from oven and cool 5 minutes. Cut, on a diagonal, into 1/2" slices. Place the slices upright on the baking sheet, return to the oven and bake for 5 more minutes. When cool, serve with a cup of tea or coffee.