In a medium bowl, combine peanuts, sugar, and peanut butter. If the mixture is too dry and won't hold together, add a little more peanut butter. Divide into 24 equal pieces.
In a large bowl, combine rice flour and water until it comes together. Continue to knead until no longer sticky. Divide into 24 equal pieces. Flatten a piece into a circle and place a piece of peanut filling in the center. Form the edges over the filling and seal, making sure all the filling is enclosed. Gently roll into a ball. Repeat with remaining pieces.
In a medium pot, bring 5 cups of water to a boil. Reduce heat to medium and add ginger and screwpine leaves, if using. Boil for 10-15 minutes. Stir in the sugar and continue to boil for 5 minutes. Reduce heat to medium low and simmer until the syrup reduces to about 4 cups. Taste the syrup and add a little more sugar if needed.
Bring a large pot of water to a boil. Add the dumplings and boil until they rise to the surface, about 5 minutes. Remove the dumplings with a slotted spoon and place in the ginger syrup.
Serve immediately with the syrup and garnish with chopped peanuts.