Preheat oven at 180°C/350°F. Grease a springform pan and line the bottom with greased parchment paper.
Mix milk and lemon juice and let it sit for 5 minutes.
Sift together flour, salt, baking powder, baking soda and cocoa.
Beat butter until softened. Add sugar, vanilla and cream together until light and fluffy. Add eggs one at a time beating well after each addition.
Add the dry ingredients alternating with the milk and mix to combine. Do not overbeat. Pour into the prepared pan and bake for 30 minutes, or until a toothpick inserted in the center comes out clean. Let cool completely on a wire rack. Cut in half lengthwise to spread the frosting.
For the frosting: Beat butter, cream cheese and vanilla until smooth. Gradually add powdered sugar and beat for 1-2 minutes until fluffy. Fill and cover the cake with the frosting.