In a large bowl mix together the starter, milk and flour.
Cover and allow to sit for 2-3 hours (it won’t bubble but will expand a tiny bit).
Preheat the oven to 350F.
Trace 3 cake pan circles onto parchment paper.
Grease 3- 9″ round cake pans with butter, lay a parchment circle in the bottom, grease that and then tap a layer of flour in.
In a medium bowl, beat together sugar, butter, vanilla, salt, baking soda, cocoa and espresso powder (the mixture will be grainy).
Add the eggs one at a time, beating well after each addition.
Gently combine the chocolate mixture with the starter-flour mixture, stirring until smooth (this will be really goopy at first, but as you continue to beat it, the batter will smooth out).
Equally distribute the batter among the three cake pans.
Bake 20 minutes, rotating halfway through.
Remove from the oven and cool in the pans on a wire rack for 10 minutes.
Turn the cakes out onto the wire rack to cool completely.
Cream Cheese Frosting
Cream together the butter and cream cheese until smooth.
Add in the vanilla and salt and mix until combined.
Slowly begin adding in the powdered sugar, mixing until all the sugar is added and combined..
(If the frosting is too thin, add more sugar – if too thick, add a tsp or two of water).
+Note: This cake totally calls for a stand mixer. Don’t even attempt to kill your arms by mixing it by hand, or using a hand mixer. Then batter is very thick and strong. Use a stand mixer!+