Make the cream cheese filling first: Combine the cream cheese, granulated sugar, sour cream, heavy cream and vanilla in a mixing bowl and beat until smooth and creamy. Add egg and beat just until incorporated. Set aside.
Make the cake: Position a rack in the lower third of the oven and preheat to 350 degrees F. Generously coat a 6 inch Bundt pan with flour-added baking spray or grease with shortening and dust with flour.
In a mixing bowl, whisk together the flour, sugar, cocoa powder, baking soda and salt.
In a second bowl, whisk together the vegetable oil, sour cream, egg, food coloring, vanilla, vinegar and water.
Pour the wet ingredients into the dry ingredients and whisk until just combined.
Spread 1 1/2 cups of the batter in the prepared pan. Carefully pour in the cream cheese mixture, then spoon the remaining cake batter evenly over the top.
Bake for 55-60 minutes or until the top is cracked, edges are slightly browned and cake pulls away from the pan. Transfer to a rack and let cool 20 minutes in the pan, then carefully invert onto a plate and let cool completely.
Make the glaze: Combine the cream cheese, confectioners' sugar, sour cream, vanilla and salt and beat until smooth. Pipe or spread over the cake.