Cinnamon Swirl Coffee Cake {Gluten Free}

My hubby was busy baking today! I love it when he bakes, not only because he makes delicious creations but because I really don't care for baking, much too specific for me. I like to play around with recipes, adding things and leaving things out and that just doesn't work with baking. Today's creation was this delicious cinnamon swirl coffee cake and it was fantastic!! Seriously people, this is on par with my favorite sour cream coffee cake I grew up eating and still love to make every Christmas Eve. You would never guess that it's gluten free and that it has been lightened up; another trait I love in a good baked item. If you aren't interested in gluten free, still try this one, I've listed the alternate ingredients to substitute. Enjoy, and let us know what you think!

Recipe: (serves 8-9)
Ingredients:
1 cup walnuts, chopped finely
1/4 cup sugar
1/3 cup brown sugar
1 Tablespoon cinnamon

The cake:
2 cups Gluten Free Baking and Pancake Mix such as Pamela's (or 2 cups all purpose flour)
1/2 teaspoon of baking powder (or 3 teaspoons baking powder if using all purpose flour)
1 cup sugar
1/3 cup butter
2 large eggs
1 teaspoon vanilla
1 cup nonfat plain yogurt

Directions:
1. Preheat oven to 350'F. For the cake: mix four, baking powder, and sugar together; cut in the butter. In a separate bowl beat eggs then mix in vanilla and yogurt. Stir dry ingredients into wet slowly and stir to combine.
2. For the filling: Mix chopped walnuts with sugars and cinnamon. Spray an 8"x8" glass dish with cooking spray and place half the cake batter in the dish and smooth to make an even layer.
3. Next, sprinkle 2/3rds of the filling mixture on top of the first layer of batter.  Pour remaining cake batter in next and smooth carefully with a spatula. Finally, sprinkle the rest of the filling evenly on top.
4. Bake in a 350'F oven for 40-50 minutes. Cool for 5-10 minutes, serve warm.