Preheat oven to 350 degrees F. Grease 10-inch angel food tube pan.
In small bowl, mix together filling ingredients. Set aside.
In a separate bowl, make the topping by whisking together the sugar, salt, flour, and cinnamon. Add the melted butter, stirring until well combined. Set aside.
To make the cake, sift together the flour, baking powder, baking soda, and salt. Set aside. In the bowl of your stand mixer, cream together butter and sugar using the paddle attachment on high speed until light and fluffy. Stir in eggs and vanilla on low speed until combined. Beat in the flour mixture alternately with the sour cream. Do not over mix.
Spread ⅓ of the cake batter in the prepared pan. Sprinkle with ½ of the filling mixture. Cover with another third of the cake batter, then the remaining filling, and then the remaining cake batter.
Sprinkle the topping mixture over the batter in the pan.
Bake in the preheated oven for 60 minutes, or until a toothpick inserted into the center of the cake comes out clean. Cool in pan for 10 minutes, then lift bottom out of pan (remove sides) to allow cake to finish cooling. Once completely cool, you can loosen the cake from the center and bottom with a knife and then use a couple spatulas to lift the cake off of the cake pan bottom and transfer to a platter.
Best if served the same or very next day. Store in an airtight container.