In a small bowl beat the butter and sour cream until light. Gradually add the brown sugar, beating until the mixture is very light and thick. Incorporate the eggs one at a time; beat in the vanilla.

Sift together the flour, baking powder, baking soda, cinnamon and salt. Add gradually to the creamed mixture. Divide the dough into three equal parts, wrap each part in lightly floured plastic wrap, then refrigerate the dough for at least two hours.

Meanwhile, combine the figs and water in a heavy saucepan and simmer, covered for 30 mintues, or until the fruit is soft. Add the sugar, lemon peel and salt, and simmer, covered, for 15 mintues longer. Press the mixture through the coarse disk of a food mill. Cool.

On a well-floured board, roll one piece of chilled dough into a rectangle about 5 by 11 inches (12 by 28 cm). Spread one third of the fig filling along one side of the dough, covering an area roughly 2 inches (5 cm) wide and 10 inches (25 cm) long, leaving margins of about 1/2 inch (1 cm) on the edges. Mound the filling slightly along its length, then moisten the exposed margins with water. Very gently, lift the uncovered dough with a spatula and fold it over the filling. Press it down, then trim the edges and shape the roll into a neat half cylinder about 11 inches (28 cm) long and 2 to 2 1/2 inches (5 to 6 cm) wide. Place the filled roll on a large baking sheet that has been buttered lightly or covered with parchment paper.

Repeat the filling operation wth the remaining two thirds of the dough and filling, then bake the three rolls in a preheated 350F (180 °C) oven for 25 minutes, or until they are ightly browned.

Cool the rolls briefly on a rack. Then with a sharp, serrated knife, trim off the ends of each roll and cut it into slices about 1 1/2 inches (4 cm) thick. Replace the slices on the rack. When the fig bars are completely cool, store them in an air-tight container.