For filling, in a 10-inch skillet cook Italian sausage, carrot, and onion until sausage is brown and onion is tender. Remove from heat and drain off any fat. Blend in cream cheese. Stir in spinach, pecans, and bread crumbs.
On a lightly floured surface roll dough to a 12x9-inch rectangle. Carefully transfer to a greased cookie sheet. Spread the filling lengthwise in a 3-inch-wide strip down the center of the rectangle to within 1 inch of the ends.
On both long sides, make 3-inch cuts from the edges toward the center at 1-inch intervals. Moisten the end of each dough strip. (This will help to seal the dough when overlapped.)
Starting at one end, alternately fold opposite strips of dough at an angle across the filling. Slightly press the moistened ends together in the center to seal. Cover and let rise in a warm place until nearly double (about 30 minutes).
Bake in a 350 degree F oven for 25 to 30 minutes or until the loaf is golden brown. Brush the top with melted margarine or butter. Cool slightly on a wire rack before cutting. Serve with German-style mustard, if desired. Cover and refrigerate any leftover bread. Makes 10 to 12 side-dish servings.