Rusks are hard cookies that are similar to biscotti. Depending on who you talk to, rusks are said to have Finnish, Dutch, German, or South African origins. Like biscotti, they are twice-baked and often served with coffee or tea, to be dunked in the hot beverage.
In order to make rusks, preheat an oven to 325° F (163° C). Beat half a cup (118 ml) of unsalted butter until it is soft, then add in half a cup (118 ml) each of white and brown sugar. After the sugar and butter is creamed, beat in two eggs, one at a time. Next, add one teaspoon (5 ml) vanilla extract and half a cup (118 ml) of sour cream, beating until the mixture is smooth.
Sift together 3 cups (710 ml) of unbleached white flour, half a teaspoon (2.5 ml) of salt, and half a teaspoon (2.5 ml) of baking soda. Mix the dry ingredients for the rusks into the butter mixture a little at a time. When this is mixed, add in one cup whole wheat pastry flour, one half cup (120 ml) of finely chopped nuts and one quarter cup (60 ml) roughly chopped nuts. Walnuts and almonds are both commonly used, although other nuts may also be used. If the dough becomes too stiff to mix with a spoon, begin mixing with your hands.
Roll the rusk dough into log-shaped rolls, about one inch across. Lay these long rolls on a cookie sheet, and bake them in the preheated oven for about 40 minutes, or until they are a nice golden brown color. Remove the cookies from the oven, and turn the oven down to 300° F (149°).
Next, slice the cooked "logs" diagonally, so the rusk slices are no more than half an inch thick. Place the slices, now resting on a flat side (cut side down) back on the cookie sheets, and bake them in the 300° F (149°) oven for about 15 minutes, or until browned on both sides.
The rusks may now be taken out of the oven and transferred to a cooling rack. When cool, rusks are best stored in covered tins or cookie jars. Because they are twice baked and meant to hold up well while dipped in coffee or tea, the rusks are long-lasting and will not go stale quickly.
A variety of nuts may be used for rusks. Although almonds and walnuts are the most common, pine nuts and hazelnuts also make for tasty cookies. If pine nuts are being used for rusks, half of the volume should be left whole and half should be chopped. If hazelnuts are to be used, they should be roasted first in a 350° F (163° C) oven for 7 to 8 minutes, then left to cool. When the nuts are cool, they can be rubbed with a towel to loosen the skins, then chopped.