Peel pumpkin and remove seeds. Cut prepared pumpkin into small pieces, put into a pot, add 1/2 cup of hot water, cover the pot, and braise pumpkin for 15 minutes. Add milk, cooked rice, butter (30 g), sugar, and cook 15-20 minutes longer, stirring from time to time.
Put seedless raisins into a hot skillet with remaining butter, and, when raisins swell, transfer them to the pot with pumpkin, mix, and 2-3 minutes later remove from heat. Serve hot.