To begin, preheat your oven to 350 degrees. Grease & flour a tube cake pan. Set it aside for now.
In a bowl, sift together the cake flour, baking powder, cinnamon, nutmeg, fine salt, and baking soda. Set this aside.
In your mixing bowl, combine unsalted butter and sugar. Beat these together on high until they are nice and fluffy.
Add in the eggs one at a time, completely mixing the egg in before adding the next. After adding all of the eggs, add the vanilla extract. Again, mix until combined.
Add half of your flour mixture to the mixing bowl and mix until combined.
Add in 1 1/4 cup of sour cream. Mix until it is combined, then add the remaining flour mixture. Again, mix this on medium speed until it is completely mixed in. Be sure to scrape the bowl with a rubber spatula so you don't miss anything. Set this aside for a moment while you make the filling.
In a small bowl, combine the ingredients for the filling. Mix these together with a fork, mash it against the side of the bowl until it becomes a crumbly mixture.
Spoon half of the cake batter into the prepared cake pan. Smooth the batter with the back of the spoon.
Sprinkle the filling all over the batter.
Carefully spoon the remaining batter into the pan over the filling, again smoothing it with the back of your spoon or spatula.
Bake the cake for 50-60 minutes or until it tests done in the center with a wooden tooth pick.
Cool it in the pan on a rack for 10 minutes and then transfer it to a platter.
To finish it off, I like to make a simple glaze to go over the top.
In a small sauce pan, combine the butter, sugars half & half, and cinnamon. Turn the heat on medium low, whisk it all together, letting it come to a gentle boil. Let it bubble for 1 minute and remove from heat. Stir in the vanilla. Let this cool until it is just warm, stirring occasionally while it cools. As it cools, it will thicken a little. When it starts to thicken, give it a whisking then drizzle it over the top of the cake.
Serve a slice with your morning coffee and start Thanksgiving off right.