Prepare 4 cake pans using parchment circles in the bottom of each pan and lightly coating the sides and paper with butter. I use 9 inch round cakes pans.
Preheat oven to 350
Blend flour, salt, baking soda, cocoa and sugar together, set aside
Make sure all of your wet ingredients are at room temperature.
In the bowl of your mixer whip softened butter and yogurt together .
Add the eggs one at a time fully incorporating before adding another, and remember to scrape down your bowl in between each addition.
Add vanilla and mix until blended
Add the dry ingredients and mix just enough to blend them into the wet ingredients.
Divide between 4 cake pans,spreading batter evenly using an offset spatula
Bake 20-25 minutes or until a toothpick inserted in the center comes out clean
Cool on wire rack for 10 minutes then remove from pan to continue cooling.