Not Unhealthy Oatmeal Cake

Still experimenting with baking. Saw this recipe in the Penzy's catalog and it reminded of a cake I frequently made when I was a teenager. I cut back on the sugar and used unsweetened coconut. You probably already have most of the ingredients in your pantry and so it's a good choice when you need to bring something to a potluck or you want something sweet with no fuss. And oatmeal is a whole grain, right?

Not Unhealthy Oatmeal Cake

Cake:
1 cup quick-cooking or regular oats
1 1/4 cups boiling water
1/2 cup (1 stick) butter, softened
1 cup sugar (I used 3/4)
1 cup brown sugar (I used 3/4)
2 eggs
1 tsp. vanilla extract
1 1/2 cups all-purpose flour
1 tsp. baking soda
1/2 tsp. salt
1 tsp. cinnamon

Topping:

1/4 cup butter, softened
1/4 cup heavy cream (I used 2% evaporated milk)
1 cup packed brown sugar
1 cup shredded coconut (I used Bob's Red Mill dried unsulfured, unsweetened coconut)

Preheat oven to 350 degrees. Grease or use cooking spray for a 9x13 pan - use a baking pan, not a glass casserole dish, as the topping will need to be broiled briefly.
Combine oats with the boiling water in a medium bowl and let stand for 5-10 minutes until soft and water is absorbed.
Meanwhile, in a mixing bowl, cream the sugars and the butter till fluffy. Add the oats and mix. Add the eggs and vanilla and mix very well.
In a separate bowl, stir together the flour, soda salt and cinnamon. Gradually add to the oats/sugar mixture and mix well.
Pour into pan and bake for 30-35 minutes or until knife comes out clean.
Turn on the broiler. In a separate bowl, combine the topping ingredients and mix well. Spread evenly over the warm cake (if you like a lot of icing, you may want to double the ingredients. ) Place the cake under the broiler 2 inches from the heat and broil until lightly browned.