Sift together the flour, sugar, salt and baking powder.
Cut in the butter and then add the breadcrumbs.
Add egg, marmalade and enough milk to give a soft dropping consistency.
Pour mixture into a greased pudding basin or bowl and cover with a double sheet of waxed paper.
Tie securely around the top of the bowl with butcher''s twine.
Place bowl into large pot such as a Dutch Oven with enough water to reach half way up the exterior of the bowl.
Bring to the boil and steam (covered) on low heat for two hours.
For sauce, heat water, marmalade, lemon juice and sugar in a small saucepan.
Combine cornstarch with a little water and add, stirring till sauce reaches desired consistency.
Turn finished pudding out onto a plate and top with the marmalade sauce before serving with custard.