Preheat the oven to 350°F. Spray a 9-inch springform pan with non-stick cooking spray. Set aside.
In the bowl of an electric mixer, combine yogurt, 1 tablespoon butter, sugar, and sugar substitute for 2 minutes on medium low speed. Add in eggs one at a time with the mixer on Low. Add the vanilla extract, and mix on Low for another 30 seconds.
Add in the cinnamon, whole wheat pastry flour, baking soda, and salt. Mix on medium low for about 30 seconds. Scrape down the sides, and mix again for another 30 seconds or until the dough is just combined.
Transfer to the prepared springform pan.
In a small bowl, stir together the topping ingredients {butter, cinnamon, brown sugar}, and dollop mixture onto the dough in the springform pan. Use a fork or knife to swirl the dough.
Put it in the oven and bake for about 30 to 35 minutes or until a toothpick or cake tester comes out clean.
Right before the cake comes out of the oven, stir together the cream cheese, powdered sugar, vanilla extract, and about 1 teaspoon milk. Add more milk as needed to get it to your desired glaze consistency.
Let the cake cool in the pan for about 5-10 minutes then pop off the sides and cut into pieces. Drizzle the glaze over the cake and serve. Enjoy!