In a large pot, combine water, maple syrup, rum, and 1/2 teaspoon salt; bring to a boil.

In a food processor, blend flour, baking powder, baking soda, and remaining salt. Add cold butter and pulse until coarse crumbs form. Mix in buttermilk until a soft dough forms; avoid overmixing.

Gently drop spoonfuls of dough into the simmering sauce. Cover the pot and reduce heat; simmer for about 10 minutes, until the dumplings are cooked through.

Carefully transfer the cooked dumplings to an oven-safe dish; keep warm while repeating with remaining dough.

Ladle the remaining sauce over the dumplings and serve warm, optionally topped with whipped cream or ice cream.