Preheat oven to 350 degrees.
Grease and flour a 13x9 pan.
Pour boiling water over oats, cover and let stand 20 minutes.
Beat butter until creamy, gradually add granulated sugar and brown sugar, beating until fluffy.
Blend in vanilla and eggs, then add oatmeal mixture, mix well.
In separate bowl, sift together flour, baking soda, salt, cinnamon and nutmeg.
Add to creamed mixture and mix well.
Pour into pan and bake for 50-55 minutes.
Remove from oven and frost while warm.
Icing: Change oven to broiler temperature. Mix all ingredients together. Spread over cake and put under broiler. WATCH CLOSELY – BROIL UNTIL IT IS BUBBLY THEN REMOVE, IT BURNS EASILY.