Generously butter a 7 1/2-cup steam pudding mold, set aside. In a large saucepan, combine cranberries, sugar, kirsch, and cinnamon stick. Place over medium-high heat and bring to a boil. Reduce heat to medium and simmer uncovered, stirring occasionally, for 10 to 12 minutes or until cranberries break down and mixture thickens. Remove from heat, discard cinnamon stick, and cool.
Evenly spread 1/2 cup of the cooled cranberry mixture onto the bottom of the pudding mold, set aside. Meanwhile, prepare the water bath: Fill a large pot (11-by-5 1/4-inches) one-third full with water. Place over a high heat and bring to a boil. Reduce heat to low, cover, and keep at a simmer until pudding is ready to cook.
Sift together in a medium bowl the flour, baking powder, and salt. In a large bowl with an electric mixer, beat the butter and brown sugar until light and creamy, about 4 minutes. Add the eggs one at a time, mixing until completely blended. Add the vanilla.
Add the dry ingredients alternately with the milk in three additions, beginning and ending with the dry ingredients and blending well after each addition. Add the dried cranberries and the remaining cranberry mixture to the batter and mix until well blended. Pour batter into pudding mold to within 1/2 inch of the top, cover tightly with the moldâ??s lid.
Submerge a folded dish towel onto the bottom of the large water-bath pot or fit with a wire rack. Place the pudding mold into the water bath, resting on the towel, so that the water comes halfway up the sides of the mold. Cover the water bath and gently simmer the pudding for about 2 hours and 20 minutes or until set and a knife inserted into the center comes out clean.
Remove pudding mold from the water bath and cool 15 minutes on a wire rack. Unmold pudding onto a serving platter. Serve with kirsch-flavored whipped cream, if desired.