Cream sugar and butter together in a large mixing bowl until light and airy.

Add sour cream and milk to bowl and mix until incorporated.

Add eggs and vanilla and mix.

In a separate bowl, sift together dry ingredients.

Add dry ingredients to the bowl of wet ingredients and mix until fully combined.

To make the filling, combine the brown sugar and cinnamon in a medium mixing bowl. Add the butter and mix well. Set aside.

Spread cinnamon roll cake batter into your prepared sheet pan. Cover with filling and spread gently to coat evenly.

Bake for 23-25 minutes, then remove from oven and allow to cool.

In a medium saucepan, add the butter, granulated sugar, whipping cream, vanilla and corn syrup and bring to a boil. Boil for 3-4 minutes and allow it to thicken slightly.

Remove from heat and stir in the cream cheese.

Return to burner and stir continuously until the cream cheese has melted.

Remove from heat and add 3 cups powdered sugar (I do the last cup slowly to make sure I get the right consistency) stirring until well combined.

Allow icing to cool slightly, then pour over the cinnamon rolls.

Once icing sets, cut into squares and serve.