This is a chocolate lovers dream, chocolate upon chocolate. Mix your wet ingredients: melted butter, sugar, yogurt, eggs and vanilla. Add 3/4 of your chocolate chips to your wet ingredients. In a separate container sieve and mix your dry ingredients, Flour, baking soda  and cocoa, and a pinch of salt.
Tip:
Vanilla and salt help heighten flavor when backing, so whatever recipe you follow you always want to keep that in mind and include it if its not already included. 

Fold in your dry ingredients into your wet ingredients and mix.