Preheat the oven to 350 degrees. Line a baking sheet with a silpat mat.
Combine the flour together with the baking soda and salt; mix well. Melt the butter in a large microwave safe bowl; add the sugars, cocoa, and vanilla then mix until well combined. Add the yogurt and mix. Slowly add the flour mixture to the cocoa mixture until well combined.
Place spoonfuls on the silpat mat about 2 inches apart. Place into the oven and bake for 8-10 minutes. Remove from the oven then let cool on baking sheet for 5 minutes. Move the cookies to the wire racks to finish cooling. Serve with ice cold milk. Enjoy.