Remove any stem. Cut the pumpkin in half and clean out the innards. Cut the pumpkin in 1.5-inch slices.
In a large saucepan add the water, piloncillo, cinnamon sticks, and orange zest and juice. bring to a boil.
Carefully place the pumpkin slies in the saucepan and reduce heat to low. Cover partially and simmer for one to 2 hours, until pumpkin is tender and the liquid has reduced.
Remove from heat and leave to cool. Serve at room temperature on its own, with pepitas, ice cream, or a bit of mlik.