Prepare steamer pot, bring water to boil on high heat, then lower the heat to medium while preparing batter
Mix coffee with cooking oil, set aside
Mix eggs and sugar using wire whisk, set aside
Combine dry powder well
Into eggs mixture, stir in dry mixture and coffee mixture alternating each other. Start with adding dry then wet then dry
Pour batter into mold, sprinkle with chopped walnuts and steam for 30 minutes
Cool on rack