Preheat the oven to 350°F. Lightly grease a 12’’ round pan or 9" x 13" pan.
Prepare the topping by mixing together sugar, flour, and cinnamon. Once it is combined add melted butter, stirring until well combined. Set aside.
Prepare the filling by stirring together all of the ingredients in a small bowl, set aside.
Make coffee cake by beating together applesauce, butter, salt, sugars, baking powder, and vanilla in a large mixing bowl until smooth.
Add the eggs one at a time, beating well after each addition.
In a small bowl whisk together the fat-free sour cream and skim milk until well combined.
Slowly alternate adding small amounts of the flour and milk mixture into the butter mixture until well combined.
Pour ½ of the coffee cake batter into the prepared pan.
Then sprinkle the filling evenly on top of the coffee cake batter.
Spread the remaining batter over the filling. Then use a knife to gently swirl the filling into the batter. Like you would when making a marble cake. Don’t over swirl it, because then you will mix the two and not see the swirl. I go through the cake once and call it good.
Now sprinkle the topping evenly over the coffee cake.
Place in pre-heated oven and bake 55-60 minutes or until the cake until has dark golden brown edges; and a toothpick inserted into the center comes out clean.
*Tip to tell if it is done, press gently in the middle if it springs back it is done.
Once coffee cake is done remove from oven and cool for 20-30 minutes.
Cut, serve and devour!