GF Coffee Cake 1.0

This is my first attempt at gluten free cake, cobbled together from about three recipes online, maybe four. It turned out pretty edible, to my surprise and delight. It took 80 minutes to bake, rather than 50, and was still gummy, but that's what this recipe is for-to tweak. Also, I weigh my flours and brown sugar. The results are more reproducible.

Topping/filling:
2/3 c. (80 g.) oat flour
3/4 c. (6 oz.) brown sugar
3 T. cold butter
2 t. cinnamon
2/3 c. chopped pecans, toasted at 350 for about 10 min, or till they smell good. (Next time I'll use 3/4 c.)

Cake:
1 c. (8 oz.) butter, softened
1 c. sugar
1 c. (8 oz.) brown sugar
2 eggs, added one at a time
1 t. vanilla
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2 c. (272 g.) Bob's Red Mill all purpose flour baking mix*
1 1/2 t. xanthan gum
1 1/2 t. baking powder
1/4 t. baking soda
1 t. cinnamon
1/4 t. salt
1 c. (8 oz.) sour cream 

Directions:

Topping: cut cold butter into oat flour, brown sugar and cinnamon. Mix in toasted chopped pecans. Set aside.

Cake: cream sugars and softened butter till light and fluffy. Mix in vanilla, then eggs, one at a time. Beat well.  In separate bowl blend all the dry ingredients. A wire whisk does a good job of blending them. Add dry ingredients alternately with sour cream, ending with dry. I folded them in, trying to not deflate the airy texture of the creamed mixture. Not so sure it worked. 
The recipe says to pour half into a  greased 10" bundt pan, but lacking that I used a 9 1/2" springform pan, then sprinkle about half (half seemed excessive, so I used about 1/3 and wished for more pecans) the topping/filling over it. Spoon in the rest of the batter. Smooth the top and sprinkle with the rest of the topping.

Bake at 350 for "45-50 minutes", but a toothpick came out clean for me after 80 minutes, and the middle fell badly.


Notes to self: 
1. Next time,  use two smaller springform pans (because I have them) and cook for the full 80 minutes, unless the edges burn first. Soggy middles are a letdown. A thinner cake may be the answer?
2. Use more pecans and less oat flour and sugar in the topping. Try 1/2 c oat flour, 1/2 c. (4 oz.) brown sugar, 1 1/2 t. cinnamon and 3/4 c. toasted chopped pecans.
3. Beware of the bean flours, even though they taste lovely once baked. They kick back later.


*Bob's Red Mill All Purpose GF Flour Mix contains:
     garbanzo bean flour
     potato starch (NOT the same as potato flour)
     tapioca flour (same as tapioca starch)
     white sorghum flour
     fava bean flour

Another recipe that looked interesting made the cake with:
1/4 c. canola oil
1 egg, beaten
1/2 c. almond milk
1 t. (or less) almond flavoring
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1 1/2 c. (204 g.) Bob's Red Mill gluten free flour mix
3/4 c. sugar
2 t. baking powder
1/4 t. salt

Mix wet ingredients well.  Mix dry ingredients in separate bowl, add to wet ingredients.
Pour into 8"x8" pan.
Bake at 375 for 25 minutes.
Drizzle with 1/2 c. powdered sugar, 1/2 t. vanilla and 1T. milk.

I would try it with the pecan topping, not the wet drizzle.