Put pumpkin into a pan, half-cover with water and bring it to boil.
Meanwhile rinse the rice, place it in a pot with 1 cup of water and bring to a boil. Reduce heat, cover and let it simmer until water is absorbed. Take off heat and set aside.
When pumpkin is soft, mash it with masher or hand-blender. Add rice, milk, raisins and sugar. Bring to boil, stirring occasionally.
Remove from heat once liquid has almost evaporated. Serve warm.
Note: Amount of sugar needed can vary depending on sweetness of pumpkin.