Feeding Teenagers-or-Easy Peasy Apple Coffee Cake

I just put coffee in the title of the cake because making it an official coffee cake gives me a good excuse to have a cup of coffee when eating it. And we are feeding lots of teenagers these days--two Bible Study groups on Thursday night and the worship band last night--so I was trying to think of a fast, easy, somewhat healthy snack cake that I could make. I made three of these cakes on Thursday and wanted to try something new on Friday so adapted this apple muffin recipe to a cake. 15 minutes from inspiration to oven and the apples go into the blender, peel and all. Couldn't be easier!

Blender Apple Coffee Cake

3 cups all-purpose flour
1 cup whole wheat flour
4 tsp baking powder
1/2 tsp baking soda
1 tsp salt
1 1/2 tsp cinnamon
1 cup milk
2 eggs
2/3 cup canola oil
2 cups brown sugar
5 small-medium red apples (though I've used yellow and green)
1/2 cup walnuts or pecans

1. Mix flour, baking powder, soda, salt, and cinnamon in a large bowl.
2. Blend in blender: apples (cored and cut into eighths), milk, oil, eggs, sugar, and nuts. These ingredients just about max out my Bosch blender so if you have a small bender you might want to blend in two batches. A food processor may work as well, though I haven't tried it.
3. Pour into a large (10''X13''), greased, baking dish/pan.
Optional but desirable~ sprinkle with crumb topping (recipe below)
4. Bake at 350 degrees F (medium oven) for about 30 minutes.

Nice served with a dollop of lightly sweetened whipped cream.

Crumb Topping:

1/2 cup brown sugar (we like dark)
1 cup flour
1/4 pound butter, chilled
chopped pecans or walnuts

In a bowl, mix sugar and flour until blended. Cut the chilled butter into smaller pieces and rub the butter into the flour mixture with your fingers until the mixture resembles coarse crumbs. Add finely chopped pecans or walnuts to taste. If you have leftover crumb topping, it stores well in the freezer and makes a nice topping for muffins.