Cream Cheese Coffee Cake

This is also from Cook's country, too. I've modified the recipe to accommodate for gluten-free baking

In a bowl, whisk together:
2 1/2 cups flour
1 tsp. salt
1 1/8 tsp. baking powder
1 1/8 tsp. baking soda
1 1/2 tsp. xanthan gum
Cream 1 cup + 2 tbsp. sugar, 10 tbsp. of unsalted softened butter, and 1 tbsp. lemon zest. Mix on medium speed for about 3 minutes until light and fluffy. Scrape bowl down and add 4 room temperature eggs, one at a time. Incorporate well after each addition. Add 4 tsp. vanilla.

On low speed, add 1/3 of the dry ingredients, then half of 1 1/4 cups sour cream, then half of the remaining flour mixture, then the rest of the sour cream, then the rest of the flour. Mix for about 10 more seconds then turn off the mixture and finish by mixing by hand making sure to scrape the bottom of bowl well. Reserve 1 and 1/4 cup of batter, separated.

Fill prepared angel cake or bundt pan with 2/3 cups of batter. Smooth top.

In same mixing bowl (no need to wash it) prepare filling by adding 8 oz. softened cream cheese, 5 tbsp. of sugar, 1 tsp. vanilla, and 4 tsp. fresh lemon juice. Mix on medium until light and creamy, about 1 minute. Add 1/4 cup of batter into mixture and mix until incorporated.
Add cheese filling to cake pan carefully placing the filling in the middle (avoid the sides) and smooth the top.
Add last 1 cup of cake batter and smooth on top making sure to cover the filling. Then take spatula and stick it ino the cake pan to swirl cheese filling. Tap cake pan a couple of times to release bubbles.
Stir together 1/4 cup sugar and 1 1/2 tsp. lemon zest. Mix together and add 1/2 cup nuts (optional, maybe some toasted squash seeds if you have a nut allergy). Add to cake and press in.

Bake in a 350 degree oven on the middle rack for 45 to 50 minutes or until a toothpick stuck into the cake comes out clean. When done, cool for 1 hour in the pan then invert onto a cookie sheet then onto a wire rack so that the topping is top-side up. Cool to room temperature (about 2 hours more), then serve.