Combine flour and baking powder. In large mixer bowl beat butter and sugar until blended. Beat in eggs, lemon peel, almond extract and saffron. Beat in flour mixture until well blended. Stir in almonds. Divide dough in half. Shape each portion into a 12x2x1-inch loaf. Place 15 cm apart on a lightly greased cookie sheet. Beat the egg white until foamy. Brush over tops of loaves. Bake in 190ºC oven 20 to 25 minutes or until light brown. Cool on cookie sheet about 1 hour. Cut each loaf diagonally into 1 cm thick slices. Lay slices, cut side down, on cookie sheet. Bake in a 160ºC oven 10 minutes longer or until dry and crisp. Cool on wire rack. These cookies are good made several days ahead and stored in a paper bag to soften slightly. To store longer, place in a covered container. Makes about 36 cookies.