Gluten Free Coffee Cake

Prep: Preheat oven to 350℉. Prepare loaf pan by lining it with parchment paper and leaving little flaps on both sides, so you can pull out the loaf after it's baked.
Wet Ingredients: Beat ½ cup butter ½ cup pure cane sugar, and ½ cup coconut sugar together with a stand mixer or electric hand mixer. Add 1 teaspoon vanilla extract and 1 egg at a time and beat, about 2 minutes.
Dry Ingredients: Mix 2 cups 1-to-1 gluten free flour, 1 teaspoon baking soda, 1 teaspoon baking powder, ¼ teaspoon kosher salt, & ¼ teaspoon xanthan gum together in a separate bowl.
Combine: Add a little of the flour mixture to the wet ingredients and mix. Then add in some yogurt and mix again. Continue to alternate mixing in the flour mixture and yogurt until everything is combined (the batter will be very thick).
Streusel: In a small bowl, add ½ cup brown sugar, ½ cup walnuts, 6 tablespoons pure cane sugar, and 1 teaspoon ground cinnamon.
Layer: In the prepared pan, alternate adding in the batter and the streusel mixture, to form at least 3 layers of each ending with a layer on top (Layers: batter, streusel, batter, streusel, batter, streusel).
Bake: Place in the preheated oven at 350℉, middle rack, and bake for 45-50 minutes or until tester comes out clean.
Cool + Serve: Remove from the oven, keep in the pan on the cooling rack for 10 minutes. Carefully remove the coffee cake from the pan and let cool for 1 hour. Cut and serve!