Cream margarine and sugar together until light and fluffy. Blend in the "eggs" and extracts. Mix in the flour and baking soda. Stir in the chocolate chips and nuts. Chill for 10 minutes.
Divide the chilled dough in half and shape into a 1 inch-thick rectangular slabs on an lined, oiled baking sheet. Flatten the slabs slightly by evenly patting them down. Bake until they are golden brown and a toothpick inserted in the center comes out clean, about 25 minutes. Remove from the oven and reduce the oven temperature to 275 degrees F.
Let slabs cool for 10 minutes, then cut each slab into 1/2 inch-wide slices. Place sliced biscottis on their sides on an ungreased baking sheet (just simply remove the lining from the one you just used) and bake for another 8-10 minutes until they are crisp and dry. Let cool completely before storing in an airtight container, where they will keep for a few days. Freezing makes them even tastier!