Preheat oven to 350. Line two 9x5 loaf pans with nonstick foil, spray heavily with cooking spray and set aside.
In a large bowl beat butter and sugar until light and fluffy. Mix in greek yogurt. Stir in heavy cream and vanilla. Add eggs one at a time, mixing well after each egg. In a separate bowl mix flour and baking soda. Add dry ingredients to wet in gredients and mix until just combined.
In a small bowl mix 1/4 cup sugar and cinnamon. Pour 1/3 of batter into loaf pans. Sprinkle half of cinnamon sugar mixure into pan. Repeat with remaining batter, then cinnamon sugar, then ending with batter.
Bake about 50 minutes or until edges begin to brown and an inserted toothpick comes out clean. If cake is not ready at 50 minutes, check again every 5-10 minutes. Allow to cool completely before gently removing from pans.
For the icing, mix together butter and cream cheese. Add cream, vanilla, and powdered sugar and mix to combine. Pour over cooled loaves. Allow to cool and set at least one hour before slicing and serving.
*Different climates and altitudes can affect the baking time of this cake, which is why the time to cook is suggested as 50-70 minutes.