What's for Breakfast? Fabulous "Penny's Apple-Brown Sugar Coffee Cake"

Can I just say this is one of the best things I've had since going off of gluten, dairy, soy and eggs? My husband made this for me this morning, and boy did he score some points!  This is adapted from my new cookbook "Cooking for Isaiah" by the chief editor for Rachel Ray (see it on the sidebar of my blog). This is something I am going to start bringing to brunch potlucks. Watch out!

Here  it is!
Serves: 8. Prep Time: 10 minutes.  Cook Time: 45 minutes

1 cup GF flour plus 2 tsp(we doubled it and used this ratio. 1 cup brown rice to 2/3 cup potato starch to 1/3 cup tapioca starch. You'll be glad you doubled it!!)
2 tsp GF baking powder
1/4 tsp salt
1 tsp xanthan gum

3/4 cup packed light brown sugar (we used maple granulated and divided into two for the two parts)
1/4 cup mini chocolate chips (we used "Enjoy Life" chocolate chips) These could be left out if you want it sugar free.
1/2 cup chopped walnuts (we omitted these)
1 tsp ground cinnamon
2 large eggs at room temperature (we used Ener-G egg replacer)
1/2 cup granulated sugar (to avoid it being too sweet since I don't eat a lot of sugar and find things sweet, we omitted this)
1/2 cup vegetable oil like grapeseed oil
2 tsp vanilla extract (we used GF Costco brand)
2 large apples -peeled, cored and cut into 1/2 inch pieces

1. Preheat the oven to 375F. Lightly grease a 9 inch springform pan or a round cake pan. In a large bowl, whisk together 1 cup flour, the baking powder and salt.
2. In a small, bowl, toss together the remaining 2 tsp flour, 1/2 cup brown sugar (or half of the total of maple), chocolate chips, walnuts (if you wish) and cinnamon.
3. In another small bowl, whisk together the eggs,granulated sugar and remaining 1/4 cup brown sugar (or the second half of the maple sugar) until smooth. Whisk in the oil and vanilla. Stir into the flour mixture until just combined. Pour half the batter into the prepared pan, and top with half the apples and half the chocolate chip mixture; repeat with the remaining batter, apples and chocolate chip mixture. Bake the cake until the toothpick inserted in the center comes out clean, about 45 minutes. Let cool in the pan and set on a wire rack. NOTE: I find the key in baking, especially GF is to not over cook it. I check it a few minutes before they say it is done and keep a close eye on it. This helps ensure it is moist, which can make the difference between a fantastic dessert and one that disappoints.  Another note if you are just starting baking GF.. .the batter when baking GF will be weird compared to wheat baking. I can't count how many times I've smeared batter in a pan and wondered if it would ever turn out. I've got so I just assume it's going to look weird and trust that "weird" batter just goes with the territory.