Preheat oven to 180°C bake. Grease and line a 20cm (approx.) round cake tin.
Cream Tararua Butter and Chelsea White Sugar until light and fluffy. Add eggs one at a time, beating well after each addition. Briefly mix in mashed feijoas.
In another bowl, stir Edmonds Baking Soda into hot Meadow Fresh Original Milk. Mix into creamed mixture.
Sift in Edmonds Standard Grade Flour and Edmonds Baking Powder into mixture and fold in until combined.
Transfer mixture to prepared cake tin. Bake for 45-50 minutes, or until cake springs back when lightly touched. Leave in tin for 10 minutes before turning out onto a cooling rack.
Mix all ingredients together in a bowl until smooth. Adjust quantity of lemon juice and water to get your desired taste and consistency.