Preheat oven to 350F. Prepare 9″ x 9″ baking pan.
Soak porridge oats with boiling water for 20 minutes.
Beat butter and sugar until well blended. Add vanilla and eggs (beating between each egg). Add cooled oats and mix together with fork, fold in flour and once mixed, pour into cake pan.
Bake for 30-40 minutes.
Comine all topping ingredients just before the cake is done. Do not remove cake from pan. Spread topping over top of cake. Then put under broiler until bubbly and golden in colour (watch carefully!).